[llvm] fix producing multiple identical opaque pointer types (PR #79060)

[Michal Paszkowski via llvm-commits]

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@@ -0,0 +1,15 @@
+; RUN: llc -O0 -mtriple=spirv32-unknown-unknown %s -o - | FileCheck %s
+
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michalpaszkowski wrote:

Could spirv-val run line be added here as well?

https://github.com/llvm/llvm-project/pull/79060