Don't try to detect the CPUID instruction if we're compiling for Pentium

If we're compiling for Pentium or better CPUs, then we know that the
CPUID instruction is present (I think it was introduced in late 486s,
actually). So don't try to detect it. Simply assume it's there and then
execute it.

This means that if you compile Qt for Pentium (or higher) and run it on
an i386 or i486, you'll get a SIGILL (or whatever your OS produces for
an #UD processor exception). If the CPU detection code even got run --
SIGILL might happen for any other instructions found along the way.

Change-Id: Iacd4a94a51363a609a61fc2bfd2e218fb290272d
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Make sure deprecation warnings don't cause errors with -Werror

It sounds like a good thing to have this warning, but for
future-proofing we can't have it. The system libraries might change
and add deprecation marks (OS X does that often). If they do that, we
don't want poor developers to have to fix all warnings before they can
build Qt again.

Change-Id: I4ff317da0de596c470bb1efe6e59bcf70aeec8fc
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Move the creation of QElapsedTimer out of the inner function in QMutex

Makes it possible for QElapsedTimer to be non-POD.

Change-Id: I5ffc59c7a93c187a4a814e6959f8383fa8d4cc44
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>