On Windows, this improves clean cmake configuration time on my
workstation from 1m58s to 1m32s, which is pretty significant. There's
probably more that can be done here, but this is the low hanging fruit.
Eric volunteered to regenerate ./configure for me.
llvm-svn: 187209
AC_CHECK_FUNCS seeks a symbol only in libs. We should check the declaration in string.h.
FIXME: I have never seen mingw(s) have strerror_s() (not _strerror_s()).
FIXME: Autoconf/CMake may seek strerror_s() with the definition MINGW_HAS_SECURE_API in future.
llvm-svn: 125172