[clang] [CLANG][MS-STRUCT] bitfield padding warning presents padding to exact bit count (PR #136062)

[Eli Friedman via cfe-commits]

efriedma-quic wrote:

If I'm following correctly, this also affects non-ms_struct definitions? Can you also add test coverage for that?

I'm not sure people will be happy to see "padding struct 'Foo' with 1 bit to align 'xx'", but I guess we can see how it goes.  Looks like gcc's -Wpadded does warn.

https://github.com/llvm/llvm-project/pull/136062