[llvm] [DebugInfo][RegisterCoalescer] Drop DBG_VALUEs with unsupported register class (PR #143132)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> Register class GR32 does not fully support subreg index sub_8bit

Is the problem the coalescer introduced a new subregister use? If we need to, we could maybe relax the verifier's rules for subregister indexes on these 

https://github.com/llvm/llvm-project/pull/143132