[llvm] [GlobalISel] Fix store merging incorrectly classifying an unknown index expr as 0. (PR #90375)

[Amara Emerson via llvm-commits]

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@@ -586,8 +594,6 @@ body:             |
   bb.1 (%ir-block.0):
     liveins: $x0, $x1
 
-    ; The store to ptr2 prevents merging into a single store.
-    ; We can still merge the stores into addr1 and addr2.
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aemerson wrote:

No but I can't seem to get the update script to keep them.

https://github.com/llvm/llvm-project/pull/90375