PERL_UNUSED_CONTEXT -> remove interp context where possible

Removing context params will save machine code in the callers of these
functions, and 1 ptr of stack space. Some of these funcs are heavily used
as mg_find*. The contexts can always be readded in the future the same way
they were removed. This patch inspired by commit dc3bf40570. Also remove
PERL_UNUSED_CONTEXT when its not needed. See removal candidate rejection
rational in [perl #122106].

-Perl_hv_backreferences_p uses context in S_hv_auxinit
 commit 96a5add60f was wrong
-Perl_whichsig_sv and Perl_whichsig_pv wrongly used PERL_UNUSED_CONTEXT
 from inception in commit 84c7b88cca
-in authors opinion cast_* shouldn't be public API, no CPAN grep usage,
 can't be static and/or inline optimized since it is exported
-Perl_my_unexec move to block where it is needed, make Win32 block, context
 free, for inlining likelyhood, private api and only 2 callers in core
-Perl_my_dirfd make all blocks context free, then change proto
-Perl_bytes_cmp_utf8 wrongly used PERL_UNUSED_CONTEXT
 from inception in commit fed3ba5d6b

1 files changed, 3 insertions, 6 deletions

diff --git a/util.c b/util.c
index d81635d09f..f2e537be26 100644
--- a/util.c
+++ b/util.c
@@ -3617,13 +3617,12 @@ Perl_init_tm(pTHX_ struct tm *ptm)	/* see mktime, strftime and asctime */
  * semantics (and overhead) of mktime().
  */
 void
-Perl_mini_mktime(pTHX_ struct tm *ptm)
+Perl_mini_mktime(struct tm *ptm)
 {
     int yearday;
     int secs;
     int month, mday, year, jday;
     int odd_cent, odd_year;
-    PERL_UNUSED_CONTEXT;
 
     PERL_ARGS_ASSERT_MINI_MKTIME;
 
@@ -5390,19 +5389,17 @@ Perl_get_db_sub(pTHX_ SV **svp, CV *cv)
 }
 
 int
-Perl_my_dirfd(pTHX_ DIR * dir) {
+Perl_my_dirfd(DIR * dir) {
 
     /* Most dirfd implementations have problems when passed NULL. */
     if(!dir)
         return -1;
 #ifdef HAS_DIRFD
-    PERL_UNUSED_CONTEXT;
     return dirfd(dir);
 #elif defined(HAS_DIR_DD_FD)
-    PERL_UNUSED_CONTEXT;
     return dir->dd_fd;
 #else
-    Perl_die(aTHX_ PL_no_func, "dirfd");
+    Perl_croak_nocontext(PL_no_func, "dirfd");
     assert(0); /* NOT REACHED */
     return 0;
 #endif