[clang] [llvm] [DebugInfo] Emit DW_AT_bit_size for _BitInt types and others (PR #164372)

[Orlando Cazalet-Hyams via llvm-commits]

OCHyams wrote:

Done - this is now very close to @dstenb 's https://reviews.llvm.org/D147625

* Add 32 bit field `DataSizeInBits` / `data_size` to `DIBasicType`.
* Add roundtrip test
* Undo changes base-type-size.ll as DW_ATE_unsigned_1 doesn't use `data_size`.

I'll open a separate pull request to include the bit-count in the name, so that can be discussed separately (it's not a regression to leave it as it is now).


https://github.com/llvm/llvm-project/pull/164372