[llvm] [IR] Add CallBr intrinsics support (PR #133907)

[Matt Arsenault via llvm-commits]

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@@ -134,8 +134,14 @@ class IntrinsicInst : public CallInst {
       return CF->isIntrinsic();
     return false;
   }
+  static bool classof(const CallBase *I) {
+    if (const Function *CF = I->getCalledFunction())
+      return CF->isIntrinsic();
+    return false;
+  }
   static bool classof(const Value *V) {
-    return isa<CallInst>(V) && classof(cast<CallInst>(V));
+    return (isa<CallInst>(V) && classof(cast<CallInst>(V))) ||
+           (isa<CallBase>(V) && classof(cast<CallBase>(V)));
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arsenm wrote:

I'm not sure if we should let these be treated as an ordinary IntrinsicInst. If we do, this should be restricted to just the CallInst + CallBr cases. Can this be left for later? 

https://github.com/llvm/llvm-project/pull/133907