[llvm] [AMDGPU] Add baseline tests for RewriteMFMAFormSchedStage (PR #193429)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,178 @@
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx90a \
+; RUN:     -amdgpu-disable-rewrite-mfma-form-sched-stage=false \
+; RUN:     < %s | FileCheck %s
+;
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx90a \
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arsenm wrote:

I think I'd just drop the MIR run lines altogether. You can tell they were rewritten from the final result 

https://github.com/llvm/llvm-project/pull/193429