[llvm] [PredicateInfo] Don't store Def in ValueDFS (NFC) (PR #145022)

[Yingwei Zheng via llvm-commits]

================
@@ -229,7 +227,14 @@ class PredicateInfoBuilder {
   void addInfoFor(SmallVectorImpl<Value *> &OpsToRename, Value *Op,
                   PredicateBase *PB);
 
-  typedef SmallVectorImpl<ValueDFS> ValueDFSStack;
+  struct StackEntry {
+    const ValueDFS *V;
+    Value *Def = nullptr;
+
+    StackEntry(const ValueDFS *V) : V(V) {}
+  };
+
+  typedef SmallVectorImpl<StackEntry> ValueDFSStack;
----------------
dtcxzyw wrote:

```suggestion
  using ValueDFSStack = SmallVectorImpl<StackEntry>;
```

https://github.com/llvm/llvm-project/pull/145022