Rename module langinfo to langinfo-h. * modules/langinfo-h: Renamed from modules/langinfo. * modules/langinfo-h-tests: Renamed from modules/langinfo-tests. * modules/langinfo-h-c++-tests: Renamed from modules/langinfo-c++-tests. * tests/test-langinfo-h.c: Renamed from tests/test-langinfo.c. * tests/test-langinfo-h-c++.cc: Renamed from tests/test-langinfo-c++.cc. * doc/posix-headers/langinfo.texi: Update. * modules/* (Depends-on): Update. * modules/langinfo: New file.