[llvm] [InstCombine] Simplify phi using KnownBits of condition (PR #134712)

[Yingwei Zheng via llvm-commits]

================
@@ -1625,6 +1625,25 @@ Instruction *InstCombinerImpl::visitPHINode(PHINode &PN) {
     return replaceInstUsesWith(PN, &IdenticalPN);
   }
 
+  if (PN.getType()->isIntegerTy()) {
+    bool MadeChange = false;
+    SimplifyQuery Q = SQ.getWithInstruction(&PN);
+    for (unsigned I = 0, E = PN.getNumIncomingValues(); I != E; ++I) {
+      Value *V = PN.getIncomingValue(I);
----------------
dtcxzyw wrote:

```suggestion
    for (unsigned I = 0, E = PN.getNumIncomingValues(); I != E; ++I) {
      SimplifyQuery Q = SQ.getWithInstruction(PN.getIncomingBlock(I)->getTerminator());
      Value *V = PN.getIncomingValue(I);
```


https://github.com/llvm/llvm-project/pull/134712