_AC_COMPILER_EXEEXT_DEFAULT removes a.*

[Ralf Wildenhues]

This is a regression from 2.59 to current CVS, I assume from the
2004-04-20 change:

touch a.c
cat >configure.ac <<EOF
AC_INIT
AC_PROG_CXX
EOF
autoconf
./configure
ls -l a.c
# ls: a.c: No such file or directory

This part seems to remove too much, for the sake of the IRIX linker:

| # List of possible output files, starting from the most likely.
| # The algorithm is not robust to junk in `.', hence go to wildcards (a.*)
| # only as a last resort.  b.out is created by i960 compilers.
| ac_files='a_out.exe a.exe conftest.exe a.out conftest a.* conftest.* b.out'
| #
| # The IRIX 6 linker writes into existing files which may not be
| # executable, retaining their permissions.  Remove them first so a
| # subsequent execution test works.
| ac_rmfiles=
| for ac_file in $ac_files
| do
|   case $ac_file in
|     _AC_COMPILER_EXEEXT_REJECT ) ;;
|     * ) ac_rmfiles="$ac_rmfiles $ac_file";;
|   esac
| done
| rm -f $ac_rmfiles

How about we remove only the output file that the IRIX linker will
actually create (iff that's the only linker with this "feature")?
I like writing test cases with files like a.c, b.c, etc., and I don't
see where the Autoconf manual forbids `a.*', au contraire, a.c is even
used in one example.

Cheers,
Ralf