Revert "reuse open(2) from rb_file_load_ok on POSIX-like system"

This reverts commit 35136e1e9c232ad7a03407b992b2e86b6df43f63.

test-spec has been failing since this revision.

.github/workflows/compilers.yml:82
https://github.com/ruby/ruby/actions/runs/4276884159/jobs/7445299562

```
env:
  # Minimal flags to pass the check.
  default_cc: 'gcc-11 -fcf-protection -Wa,--generate-missing-build-notes=yes'
  optflags: '-O2'
  LDFLAGS: '-Wl,-z,now'
  # FIXME: Drop skipping options
  # https://bugs.ruby-lang.org/issues/18061
  # https://sourceware.org/annobin/annobin.html/Test-pie.html
  TEST_ANNOCHECK_OPTS: "--skip-pie --skip-gaps"
```

Failure:

```
  1)
  An exception occurred during: Kernel#require (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded
  /__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:317
  Kernel#require (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded ERROR
  LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.ext.rb>
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:5:in `<top (required)>'

  2)
  An exception occurred during: Kernel#require ($LOADED_FEATURES) stores an absolute path
  /__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:330
  Kernel#require ($LOADED_FEATURES) stores an absolute path ERROR
  LeakError: Closed file descriptor: 8
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:5:in `<top (required)>'

  3)
  An exception occurred during: Kernel#require ($LOADED_FEATURES) does not load a non-canonical path for a file already loaded
  /__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:535
  Kernel#require ($LOADED_FEATURES) does not load a non-canonical path for a file already loaded ERROR
  LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.rb>
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:5:in `<top (required)>'

  4)
  An exception occurred during: Kernel#require ($LOADED_FEATURES) does not load a ../ relative path for a file already loaded
  /__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:551
  Kernel#require ($LOADED_FEATURES) does not load a ../ relative path for a file already loaded ERROR
  LeakError: Leaked file descriptor: 9 : #<File:../code/load_fixture.rb>
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:5:in `<top (required)>'

  5)
  An exception occurred during: Kernel#require ($LOADED_FEATURES) complex, enumerator, rational, thread, ruby2_keywords are already required
  /__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:563
  Kernel#require ($LOADED_FEATURES) complex, enumerator, rational, thread, ruby2_keywords are already required ERROR
  LeakError: Closed file descriptor: 8
  Closed file descriptor: 9
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:5:in `<top (required)>'

  6)
  An exception occurred during: Kernel.require (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded
  /__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:317
  Kernel.require (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded ERROR
  LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.ext.rb>
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:23:in `<top (required)>'

  7)
  An exception occurred during: Kernel.require ($LOADED_FEATURES) stores an absolute path
  /__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:330
  Kernel.require ($LOADED_FEATURES) stores an absolute path ERROR
  LeakError: Closed file descriptor: 8
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:23:in `<top (required)>'

  8)
  An exception occurred during: Kernel.require ($LOADED_FEATURES) does not load a non-canonical path for a file already loaded
  /__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:535
  Kernel.require ($LOADED_FEATURES) does not load a non-canonical path for a file already loaded ERROR
  LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.rb>
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:23:in `<top (required)>'

  9)
  An exception occurred during: Kernel.require ($LOADED_FEATURES) does not load a ../ relative path for a file already loaded
  /__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:551
  Kernel.require ($LOADED_FEATURES) does not load a ../ relative path for a file already loaded ERROR
  LeakError: Leaked file descriptor: 9 : #<File:../code/load_fixture.rb>
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:23:in `<top (required)>'

  10)
  An exception occurred during: Kernel.require ($LOADED_FEATURES) complex, enumerator, rational, thread, ruby2_keywords are already required
  /__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:563
  Kernel.require ($LOADED_FEATURES) complex, enumerator, rational, thread, ruby2_keywords are already required ERROR
  LeakError: Closed file descriptor: 8
  Closed file descriptor: 9
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:23:in `<top (required)>'

  11)
  An exception occurred during: Kernel#require_relative with a relative path (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:197
  Kernel#require_relative with a relative path (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded ERROR
  LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.ext.rb>
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:4:in `<top (required)>'

  12)
  An exception occurred during: Kernel#require_relative with a relative path ($LOADED_FEATURES) stores an absolute path
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:205
  Kernel#require_relative with a relative path ($LOADED_FEATURES) stores an absolute path ERROR
  LeakError: Closed file descriptor: 8
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:4:in `<top (required)>'

  13)
  An exception occurred during: Kernel#require_relative with an absolute path (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:399
  Kernel#require_relative with an absolute path (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded ERROR
  LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.ext.rb>
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:277:in `<top (required)>'

  14)
  An exception occurred during: Kernel#require_relative with an absolute path ($LOAD_FEATURES) stores an absolute path
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:407
  Kernel#require_relative with an absolute path ($LOAD_FEATURES) stores an absolute path ERROR
  LeakError: Closed file descriptor: 8
  /__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:277:in `<top (required)>'
```

1 files changed, 7 insertions, 31 deletions

diff --git a/file.c b/file.c
index 8472d94a7e..68122de6ae 100644
--- a/file.c
+++ b/file.c
@@ -6359,7 +6359,7 @@ ruby_is_fd_loadable(int fd)
 
 #ifndef _WIN32
 int
-rb_file_load_ok(const char *path, struct ruby_file_load_state *fls)
+rb_file_load_ok(const char *path)
 {
     int ret = 1;
     /*
@@ -6381,21 +6381,10 @@ rb_file_load_ok(const char *path, struct ruby_file_load_state *fls)
     }
     rb_update_max_fd(fd);
     ret = ruby_is_fd_loadable(fd);
-
-#if defined(DOSISH) || defined(__CYGWIN__)
-    fls = NULL; /* need to set xflag via open_load_file */
-#endif
-    if (ret && fls) {
-        /* TODO: avoid path object alloc in rb_io_fdopen */
-        fls->filev = rb_io_fdopen(fd, mode, path);
-        fls->is_fifo = ret < 0 ? 1 : 0;
-        fls->is_nonblock = mode == O_RDONLY ? 0 : 1;
-    } else {
-        (void)close(fd);
-    }
+    (void)close(fd);
     return ret;
 }
-#endif /* !_WIN32 */
+#endif
 
 static int
 is_explicit_relative(const char *path)
@@ -6421,13 +6410,6 @@ copy_path_class(VALUE path, VALUE orig)
 int
 rb_find_file_ext(VALUE *filep, const char *const *ext)
 {
-    return ruby_find_file_ext(filep, ext, NULL);
-}
-
-int
-ruby_find_file_ext(VALUE *filep, const char *const *ext,
-                struct ruby_file_load_state *fls)
-{
     const char *f = StringValueCStr(*filep);
     VALUE fname = *filep, load_path, tmp;
     long i, j, fnlen;
@@ -6447,7 +6429,7 @@ ruby_find_file_ext(VALUE *filep, const char *const *ext,
         fnlen = RSTRING_LEN(fname);
         for (i=0; ext[i]; i++) {
             rb_str_cat2(fname, ext[i]);
-            if (rb_file_load_ok(RSTRING_PTR(fname), fls)) {
+            if (rb_file_load_ok(RSTRING_PTR(fname))) {
                 *filep = copy_path_class(fname, *filep);
                 return (int)(i+1);
             }
@@ -6472,7 +6454,7 @@ ruby_find_file_ext(VALUE *filep, const char *const *ext,
             RB_GC_GUARD(str) = rb_get_path(str);
             if (RSTRING_LEN(str) == 0) continue;
             rb_file_expand_path_internal(fname, str, 0, 0, tmp);
-            if (rb_file_load_ok(RSTRING_PTR(tmp), fls)) {
+            if (rb_file_load_ok(RSTRING_PTR(tmp))) {
                 *filep = copy_path_class(tmp, *filep);
                 return (int)(j+1);
             }
@@ -6487,12 +6469,6 @@ ruby_find_file_ext(VALUE *filep, const char *const *ext,
 VALUE
 rb_find_file(VALUE path)
 {
-    return ruby_find_file(path, NULL);
-}
-
-VALUE
-ruby_find_file(VALUE path, struct ruby_file_load_state *fls)
-{
     VALUE tmp, load_path;
     const char *f = StringValueCStr(path);
     int expanded = 0;
@@ -6505,7 +6481,7 @@ ruby_find_file(VALUE path, struct ruby_file_load_state *fls)
     }
 
     if (expanded || rb_is_absolute_path(f) || is_explicit_relative(f)) {
-        if (!rb_file_load_ok(f, fls)) return 0;
+        if (!rb_file_load_ok(f)) return 0;
         if (!expanded)
             path = copy_path_class(file_expand_path_1(path), path);
         return path;
@@ -6523,7 +6499,7 @@ ruby_find_file(VALUE path, struct ruby_file_load_state *fls)
             if (RSTRING_LEN(str) > 0) {
                 rb_file_expand_path_internal(path, str, 0, 0, tmp);
                 f = RSTRING_PTR(tmp);
-                if (rb_file_load_ok(f, fls)) goto found;
+                if (rb_file_load_ok(f)) goto found;
             }
         }
         rb_str_resize(tmp, 0);