If the default settings already include the necessary flags, do not
override the compiler flags, possibly lowering support. This allows
the user to specify a higher setting for a Qt build, such as what
MeeGo did (it enabled SSSE3 support in all builds).
Additionally, this prevents us from passing -msse2 or -arch:SSE2
options to x86-64 builds, as SSE2 is a mandatory part of that
architecture. This silences a warning from MSVC that the option is
unknown in 64-bit builds.
Change-Id: I6e2969b672bcac87168c245b8be3309e8cc49224
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>
2988c44f76