[llvm] [AMDGPU] Enable serializing of allocated preload kernarg SGPRs info (PR #168374)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,18 @@
+# RUN: not llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx950 -start-after=amdgpu-isel -verify-machineinstrs %s -o /dev/null 2>&1 | FileCheck %s
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arsenm wrote:

```suggestion
# RUN: not llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx950 -run-pass=none -filetype=null %s 2>&1 | FileCheck %s
```

https://github.com/llvm/llvm-project/pull/168374