[llvm] [PeepholeOptimizer] Add REG_SEQUENCE subregister use folding (PR #205795)

[Matt Arsenault via llvm-commits]

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@@ -121,6 +136,10 @@ static cl::opt<bool> DisableNAPhysCopyOpt(
     "disable-non-allocatable-phys-copy-opt", cl::Hidden, cl::init(false),
     cl::desc("Disable non-allocatable physical register copy optimization"));
 
+static cl::opt<bool> DisablePeepholeRegSeqFold(
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arsenm wrote:

Don't add this option

https://github.com/llvm/llvm-project/pull/205795