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

[Robert Imschweiler via llvm-commits]

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@@ -3507,16 +3507,39 @@ void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {
                           DAG.getBasicBlock(Return)));
 }
 
+/// The intrinsics currently supported by callbr are implicit control flow
+/// intrinsics such as amdgcn.kill.
+/// - they should be called (no "dontcall-" attributes)
+/// - they do not touch memory on the target (= !TLI.getTgtMemIntrinsic())
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ro-i wrote:

added the assertion

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