[llvm] [CodeGenPrepare] Replace deleted sext instr with the promoted value. (PR #71058)

[Yingwei Zheng via llvm-commits]

================
@@ -2634,6 +2634,15 @@ struct ExtAddrMode : public TargetLowering::AddrMode {
   void print(raw_ostream &OS) const;
   void dump() const;
 
+  void replaceWith(Value *From, Value *To) {
+    if (BaseReg == From)
----------------
dtcxzyw wrote:

No. I have no idea how to generate tests that would cover all these branches :(

https://github.com/llvm/llvm-project/pull/71058