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.
'-Wstrict-aliasing=2',
'-Wwrite-strings',
'-Werror=overflow',
+ '-Werror=shift-count-overflow',
'-Wdate-time',
'-Wnested-externs',
'-ffast-math',