[llvm] [DirectX] Implement `memcpy` in DXIL CBuffer Access pass (PR #144436)

[Justin Bogner via llvm-commits]

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@@ -161,7 +164,12 @@ static void replaceAccessesWithHandle(GlobalVariable *Global,
     }
 
     // Otherwise, walk users looking for a load...
-    ToProcess.append(Cur->user_begin(), Cur->user_end());
+    if (isa<GetElementPtrInst>(Cur) || isa<GEPOperator>(Cur)) {
+      ToProcess.append(Cur->user_begin(), Cur->user_end());
+      continue;
+    }
+
+    reportFatalInternalError("Unexpected user of Global");
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bogner wrote:

We should just be using an assert/llvm_unreachable here. To hit this we need to have an actual bug in the frontend (not just some kind of malformed user input), and that's what asserts are for.

https://github.com/llvm/llvm-project/pull/144436