scons: Ensure inttypes.h is always pre-included on MSVC.
scons: Ensure inttypes.h is always pre-included on MSVC.

It's a bit hackish couldn't find another solution.  See code comment
for details.   The warning is useful, so universally disabling doesn't
sound a good idea.

Fixes

   warning C4005: 'xxx' : macro redefinition

Reviewed-by: Brian Paul <3cb4e1df5ec4da2c7c4af7c52cec8cf340a55a10@vmware.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler