[llvm] [AMDGPU] Support preloading hidden kernel arguments (PR #98861)

[Matt Arsenault via llvm-commits]

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+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -mtriple=amdgcn-amd-amdhsa -mcpu=gfx940 -passes=amdgpu-attributor < %s| llc -mtriple=amdgcn--amdhsa -mcpu=gfx940 | FileCheck -check-prefixes=GFX940-NO-PRELOAD %s
+; RUN: opt -mtriple=amdgcn-amd-amdhsa -mcpu=gfx940 -passes=amdgpu-attributor -amdgpu-kernarg-preload-count=16 < %s | llc -mtriple=amdgcn--amdhsa -mcpu=gfx940 | FileCheck -check-prefixes=GFX940-PRELOAD %s
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arsenm wrote:

I would like to see checks on the IR in the test 

https://github.com/llvm/llvm-project/pull/98861