[gcc r14-11457] libcpp: Add missing configure check for setlocale.

https://gcc.gnu.org/g:184e07c769fb93ede5aa6fdfcda80dc99051cca0 commit r14-11457-g184e07c769fb93ede5aa6fdfcda80dc99051cca0 Author: Roland McGrath Date: Thu Mar 27 22:19:03 2025 + libcpp: Add missing configure check for setlocale. libcpp/ * configure.ac: Check for se

[gcc r15-8990] libcpp: Add missing configure check for setlocale.

https://gcc.gnu.org/g:d44aa3e3bf5bd99c30bae2896c8de5cacef458fa commit r15-8990-gd44aa3e3bf5bd99c30bae2896c8de5cacef458fa Author: Roland McGrath Date: Thu Mar 27 22:17:06 2025 + libcpp: Add missing configure check for setlocale. libcpp/ * configure.ac: Check for set