[llvm-branch-commits] [llvm] Reland "RegisterCoalescer: Add implicit-def of super register when coalescing SUBREG_TO_REG" (PR #134408)

[Sander de Smalen via llvm-branch-commits]

sdesmalen-arm wrote:

My apologies for taking a while to get back to this; I had been lacking focus time, and it also took me a while to get the changes right. This time I think it's in better shape, partly because I've got a better understanding of how things work and second because I've done more testing.
(a) I've built and ran the LLVM test-suite with subreg-liveness-tracking enabled on AArch64.
(b) I've done stage-2-builds with sanitizers (address + memory) on both AArch64 and X86  with subreg liveness tracking enabled for AArch64.


https://github.com/llvm/llvm-project/pull/134408