[clang] [llvm] [NVPTX] Auto-Upgrade some nvvm.annotations to attributes (PR #119261)

[Alex MacLean via llvm-commits]

================
@@ -1270,77 +1270,21 @@ exit:
 ; MODULE: attributes #[[ATTR1:[0-9]+]] = { convergent nocallback nounwind }
 ; MODULE: attributes #[[ATTR2:[0-9]+]] = { convergent nocallback nofree nounwind willreturn }
 ; MODULE: attributes #[[ATTR3:[0-9]+]] = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: write) }
-; MODULE: attributes #[[ATTR4]] = { "kernel" }
-; MODULE: attributes #[[ATTR5]] = { nosync memory(none) }
+; MODULE: attributes #[[ATTR4]] = { "kernel" "nvvm.kernel" }
+; MODULE: attributes #[[ATTR5]] = { "kernel" }
+; MODULE: attributes #[[ATTR6]] = { nosync memory(none) }
 ;.
 ; CGSCC: attributes #[[ATTR0]] = { "llvm.assume"="ompx_aligned_barrier" }
 ; CGSCC: attributes #[[ATTR1:[0-9]+]] = { convergent nocallback nounwind }
 ; CGSCC: attributes #[[ATTR2:[0-9]+]] = { convergent nocallback nofree nounwind willreturn }
 ; CGSCC: attributes #[[ATTR3:[0-9]+]] = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: write) }
-; CGSCC: attributes #[[ATTR4]] = { "kernel" }
-; CGSCC: attributes #[[ATTR5]] = { nosync memory(none) }
+; CGSCC: attributes #[[ATTR4]] = { "kernel" "nvvm.kernel" }
----------------
AlexMaclean wrote:

I agree that `"omp_kernel"` seems like a much better name for the meaning we're currently signifying with the `"kernel"` attribute. 

> Realistically this should be a calling convention and not an attribute, but there's a lot of historical cruft around it.

@jhuber6 are you saying that the `"kernel"` attribute should be a calling convention? or that `"nvvm.kernel"` should be (similar to `amdgpu_kernel`)?

https://github.com/llvm/llvm-project/pull/119261