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

[Theo de Magalhaes via cfe-commits]

theomagellan wrote:

Hello @efriedma-quic, hope you don’t mind the ping.

This patch addresses the padded bitfield warning, which was reporting the wrong number of padded bits when using `ms_struct` and two consecutive bit-fields under the Itanium ABI.

I originally planned to merge `SemaCXX/windows-Wpadded.cc` and `SemaCXX/windows-Wpadded-bitfield.cc` into a single test file, but after some consideration, I think keeping them separate makes the coverage clearer. What do you think?

Thank you!

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