[llvm] [SelectionDAG] Mark frame index as "aliased" at argument copy elison (PR #89712)

[Matt Arsenault via llvm-commits]

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@@ -11128,14 +11128,15 @@ static void tryToElideArgumentCopy(
   }
 
   // Perform the elision. Delete the old stack object and replace its only use
-  // in the variable info map. Mark the stack object as mutable.
+  // in the variable info map. Mark the stack object as mutable and aliased.
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arsenm wrote:

Is there any practical difference between the mutable and isAliased cases? Where is the ultimate alias query that goes wrong?

https://github.com/llvm/llvm-project/pull/89712