[llvm] [DebugInfo] Make DIArgList inherit from Metadata and always unique (PR #72147)

[Jeremy Morse via llvm-commits]

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@@ -1265,9 +1265,8 @@ void SlotTracker::CreateFunctionSlot(const Value *V) {
 void SlotTracker::CreateMetadataSlot(const MDNode *N) {
   assert(N && "Can't insert a null Value into SlotTracker!");
 
-  // Don't make slots for DIExpressions or DIArgLists. We just print them inline
-  // everywhere.
-  if (isa<DIExpression>(N) || isa<DIArgList>(N))
+  // Don't make slots for DIExpressions. We just print them inline everywhere.
+  if (isa<DIExpression>(N))
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jmorse wrote:

To confirm my understanding: the mechanism of print DIArgLists isn't changing at all, but as they're no longer MDNodes,  they don't get considered for a metadata-node-number slot so don't need to appear here?

https://github.com/llvm/llvm-project/pull/72147