[clang] [llvm] [CIR][ABI] Add ABI metadata fields to RecordType (PR #188300)

[via cfe-commits]

adams381 wrote:

Gentle ping @andykaylor — all review feedback has been addressed in the latest push (Mar 24).  The three remaining fields print as optional keywords and round-trip through cir-opt.  Unit test and FileCheck lit test included.  CI is green.  Happy to make any further changes if needed.

https://github.com/llvm/llvm-project/pull/188300