[llvm] [Dwarf] Emit `DW_AT_bit_size` for non-byte-sized types (PR #137118)

[David Blaikie via llvm-commits]

dwblaikie wrote:

@jmorse seems like this might be in your/Sony's wheelhouse lately? I don't really have enough context here, but it /seems/ like if this is a C++ bool we're talking about, we shouldn't be describing it as having a smaller size but as having high bits unknown, or ideally known zero. But what to do with the expressions and the types we conjure up in the backend for them I'm less clear on.

https://github.com/llvm/llvm-project/pull/137118