[llvm] [AMDGPU] Add verification for amdgcn.init.exec.from.input (PR #128172)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,27 @@
+; RUN: sed -e '/^; MARK$/,$d' %s | not llc -mtriple=amdgcn -mcpu=gfx942 2>&1 | FileCheck %s
+; RUN: sed -e '1,/^; MARK$/d' %s | llc -mtriple=amdgcn -mcpu=gfx942 -filetype=null
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arsenm wrote:

Do not use llc in verifier tests, only llvm-as.

Also shouldn't need to use sed, simpler to test valid cases in an assembler or codegen test 

https://github.com/llvm/llvm-project/pull/128172