[lit][REQUIRES] Fix REQUIRES on an NVPTX test so it will run

[probinson]

Summary

Had to fix attributes as well, not sure which ones it should actually care about.

[tra]

Do we have any other convergent intrinsics in back-ends more common than NVPTX? If we have one in X86 or ARM that would be a better choice for this test than @llvm.nvvm.barrier0.

[probinson]

Thanks!

Do we have any other convergent intrinsics in back-ends more common than NVPTX?

Beats me. I'm just fixing tests that have undefined keywords in the various lit directives.
Naively I'd think we want tests to verify that all intrinsics have the appropriate attributes, but I'm not in a position to say what those are or where they should live.

llvm/test/Feature/intrinsic-noduplicate.ll

 ; RUN: llvm-as < %s | llvm-dis | FileCheck %s
-; REQUIRES: NVPTX
+; REQUIRES: nvptx-registered-target
 
 ; Make sure LLVM knows about the convergent attribute on the
 ; llvm.nvvm.barrier0 intrinsic.
 
 declare void @llvm.nvvm.barrier0()
 
 ; CHECK: declare void @llvm.nvvm.barrier0() #[[ATTRNUM:[0-9]+]]
-; CHECK: attributes #[[ATTRNUM]] = { convergent nounwind }
+; CHECK: attributes #[[ATTRNUM]] = { convergent nocallback nounwind }