[BitcodeReader] Avoid quadratic complexity in intrinsic upgrade

When materializing a function, we'd upgrade all calls to all
upgraded intrinsics. However, this would operate on all calls to
the intrinsic (including previously materialized ones), which
leads to quadratic complexity.

Instead, only upgrade the calls that are in the materialized
function.

This fixes a compile-time regression introduced by #149310.

Author: nikic

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -7015,13 +7015,6 @@ Error BitcodeReader::materialize(GlobalValue *GV) {
   if (StripDebugInfo)
     stripDebugInfo(*F);
 
-  // Upgrade any old intrinsic calls in the function.
-  for (auto &I : UpgradedIntrinsics) {
-    for (User *U : llvm::make_early_inc_range(I.first->materialized_users()))
-      if (CallInst *CI = dyn_cast<CallInst>(U))
-        UpgradeIntrinsicCall(CI, I.second);
-  }
-
   // Finish fn->subprogram upgrade for materialized functions.
   if (DISubprogram *SP = MDLoader->lookupSubprogramForFunction(F))
     F->setSubprogram(SP);
@@ -7037,7 +7030,7 @@ Error BitcodeReader::materialize(GlobalValue *GV) {
     }
   }
 
-  for (auto &I : instructions(F)) {
+  for (auto &I : make_early_inc_range(instructions(F))) {
     // "Upgrade" older incorrect branch weights by dropping them.
     if (auto *MD = I.getMetadata(LLVMContext::MD_prof)) {
       if (MD->getOperand(0) != nullptr && isa<MDString>(MD->getOperand(0))) {
@@ -7068,15 +7061,22 @@ Error BitcodeReader::materialize(GlobalValue *GV) {
       }
     }
 
-    // Remove incompatible attributes on function calls.
     if (auto *CI = dyn_cast<CallBase>(&I)) {
+      // Remove incompatible attributes on function calls.
       CI->removeRetAttrs(AttributeFuncs::typeIncompatible(
           CI->getFunctionType()->getReturnType(), CI->getRetAttributes()));
 
       for (unsigned ArgNo = 0; ArgNo < CI->arg_size(); ++ArgNo)
         CI->removeParamAttrs(ArgNo, AttributeFuncs::typeIncompatible(
                                         CI->getArgOperand(ArgNo)->getType(),
                                         CI->getParamAttributes(ArgNo)));
+
+      // Upgrade intrinsics.
+      if (Function *OldFn = CI->getCalledFunction()) {
+        auto It = UpgradedIntrinsics.find(OldFn);
+        if (It != UpgradedIntrinsics.end())
+          UpgradeIntrinsicCall(CI, It->second);
+      }
     }
   }