[llvm] [RegAllocFast] fold foldable inline asm (PR #74344)

[Bill Wendling via llvm-commits]

isanbard wrote:

I created https://github.com/bwendling/llvm-project/pull/1, which is a Claude reworking of this patch. It has the potential to replace the asm-constraint-br change I made.

https://github.com/llvm/llvm-project/pull/74344