meson: do not allow bit-shift overflows

The primary motivation is to catch enum values created through a shift that is
too big:

../src/test/test-sizeof.c:26:29: error: left shift count >= width of type [-Werror=shift-count-overflow]
         enum_with_shift = 1 << 32,
                             ^~
cc1: some warnings being treated as errors

The compiler will now reject those.

This is an alternative to #9224.

meson.build

@@ -319,6 +319,7 @@ possible_cc_flags = [
         '-Wstrict-aliasing=2',
         '-Wwrite-strings',
         '-Werror=overflow',
+        '-Werror=shift-count-overflow',
         '-Wdate-time',
         '-Wnested-externs',
         '-ffast-math',