do not ignore errors like ENOSPC,EIO when writing to stdout

Standard output was never explicitly closed, so we could not
detect failure.  Thus, bison would ignore the errors of writing
to a full file system and getting an I/O error on write, but only
for standard output, e.g., for --print-localedir, --print-datadir,
--help and some verbose output.
Now, "bison --print-datadir > /dev/full" reports the write failure:
bison: write error: No space left on device
Before, it would exit 0 with no diagnostic, implying success.
This is not an issue for "--output=-" or the other FILE-accepting
command-line options, because unlike most other GNU programs,
an output file argument of "-" is treated as the literal "./-",
rather than standard output.
* bootstrap.conf (gnulib_modules): Add closeout.
* src/main.c: Include "closeout.h".
Use atexit to ensure we close stdout.
* .gitignore: Ignore new files pulled in via gnulib-tool.
(cherry picked from commit acb5895680611f8beb497b41694d9686f2932c50)

Conflicts:

	m4/.gitignore

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/.gitignore b/lib/.gitignore
index 54edced3..365b84d0 100644
--- a/lib/.gitignore
+++ b/lib/.gitignore
@@ -259,3 +259,9 @@
 /strerror-override.h
 /strerror_r.c
 /xalloc-oversized.h
+/close-stream.c
+/close-stream.h
+/closeout.c
+/closeout.h
+/fpending.c
+/fpending.h