Meson already knows to test with the positive form of the flag, which
simplifies the test. Warnings are now tested explicitly for the C++
compiler, instead of hardcoding those that are only available for
the C language.
At this point all compiler flags in QEMU_CFLAGS are global and only
depend on the OS. No feature tests are performed in configure.
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
95caf1fb42