[llvm] IR: Add prefalign attribute for function definitions. (PR #155527)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,6 @@
+; RUN: not llvm-as %s 2>&1 | FileCheck %s
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arsenm wrote:

```suggestion
; RUN: not llvm-as -disable-output %s 2>&1 | FileCheck %s
```

https://github.com/llvm/llvm-project/pull/155527