[llvm] [SSAUpdaterBulk] Add PHI simplification pass. (PR #150936)

[Valery Pykhtin via llvm-commits]

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@@ -222,3 +222,94 @@ void SSAUpdaterBulk::RewriteAllUses(DominatorTree *DT,
     }
   }
 }
+
+// Perform a single pass of simplification over the worklist of PHIs.
+static void simplifyPass(MutableArrayRef<PHINode *> Worklist,
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vpykhtin wrote:

Added explaining comment.

https://github.com/llvm/llvm-project/pull/150936