MSVC supports passing /Wv and /Wv:17 to ignore warnings added
since that version. Clang doesn't have a option like this - but
we can ignore this flag instead of error.
MSVC documentation: https://docs.microsoft.com/en-us/cpp/build/reference/compiler-option-warning-level
Do we mind removing these trailing whitespaces in the same commit? I can fix that - but they shouldn't be there anyway.