AC_PROG_CXX no longer adjusts C++ language version
* lib/autoconf/c.m4 (_AC_CXX_CXX98_TEST_GLOBALS)
(_AC_CXX_CXX98_TEST_MAIN, _AC_CXX_CXX11_TEST_GLOBALS)
(_AC_CXX_CXX11_TEST_MAIN, _AC_CXX_CXX98_TEST_PROGRAM)
(_AC_CXX_CXX11_TEST_PROGRAM, _AC_CXX_CXX14_TEST_PROGRAM)
(_AC_CXX_CXX17_TEST_PROGRAM, _AC_CXX_CXX20_TEST_PROGRAM)
(_AC_CXX_CXX23_TEST_PROGRAM, _AC_CXX_CXX98_OPTIONS)
(_AC_CXX_CXX11_OPTIONS, _AC_CXX_CXX14_OPTIONS)
(_AC_CXX_CXX17_OPTIONS, _AC_CXX_CXX20_OPTIONS)
(_AC_CXX_CXX23_OPTIONS, _AC_PROG_CXX_STDCXX_EDITION_TRY)
(_AC_PROG_CXX_STDCXX_EDITION_TRY): Remove. All uses removed.
3 files changed
