year 2038 support: fix for mingw

[Bruno Haible]

When running a gnulib testdir of module 'year2038' on 32-bit mingw,
I see a 'configure' failure:

...
checking for i686-w64-mingw32-gcc option to enable large file support... 
-D_FILE_OFFSET_BITS=64
checking for i686-w64-mingw32-gcc option to enable timestamps after Jan 2038... 
-D__MINGW_USE_VC2005_COMPAT
configure: error: internal error: bad value for $ac_cv_sys_year2038_opts

The problem, as evidenced by running the configure script with 'set -x',
is that after the assignment
  ac_cv_sys_year2038_opts=-D__MINGW_USE_VC2005_COMPAT
the 'case' statement
  case $ac_cv_sys_year2038_opts in ...
does not find the value.

The attached proposed patches fix this. One for gnulib, one for autoconf.
I tested the patch for gnulib; the patch for autoconf is a trivial backport.

Bruno

0001-year2038-Fix-configure-failure-on-32-bit-mingw.patch
Description: Text Data

0001-AC_SYS_YEAR2038-Fix-configure-failure-on-32-bit-ming.patch
Description: Text Data