configure: test all warnings

Some warnings are hardcoded in QEMU_CFLAGS and not tested.  There is
no particular reason to single out these five, as many more -W flags are
present on all the supported compilers.  For homogeneity when moving
the detection to meson, make them use the same warn_flags infrastructure.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 file changed