Attached are revised patches. These are exported from trunk.


There is a change since my last message:

   * A new Makefile variable `SHLIB_MCFGTHREAD_LIBS` has been introduced, to keep
     the other thread models from being affected.


After applying these patches, configure scripts in these subdirectories need to be regenerated:

   * gcc
   * libgcc
   * libatomic
   * libstdc++-v3


The patch for libgfortran fixes

   * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105764


I have successfully bootstrapped GCC 12 with these patches, on i686-w64-mingw32 (with MSVCRT) and 
x86_64-w64-mingw32 (with MSVCRT and UCRT). No errors have been observed so far.

Once these patches land in GCC, we can start the work in mingw-w64 basing on `__USING_MCFGTHREAD__`.



-- 
Best regards,
LIU Hao