AMDGPU: Replace some undef uses in test metadata with poison (#131052)

Author: arsenm

llvm/test/CodeGen/AMDGPU/hsa-metadata-from-llvm-ir-full.ll

@@ -1779,7 +1779,7 @@ attributes #3 = { optnone noinline "amdgpu-no-completion-action" "amdgpu-no-defa
 !2 = !{!"none"}
 !3 = !{!"int"}
 !4 = !{!""}
-!5 = !{i32 undef, i32 1}
+!5 = !{i32 poison, i32 1}
 !6 = !{i32 1, i32 2, i32 4}
 !7 = !{<4 x i32> poison, i32 0}
 !8 = !{i32 8, i32 16, i32 32}
@@ -1800,13 +1800,13 @@ attributes #3 = { optnone noinline "amdgpu-no-completion-action" "amdgpu-no-defa
 !23 = !{!"none", !"none", !"none"}
 !24 = !{!"int", !"short2", !"char3"}
 !25 = !{!"", !"", !""}
-!26 = !{half undef, i32 1}
-!27 = !{float undef, i32 1}
-!28 = !{double undef, i32 1}
-!29 = !{i8 undef, i32 1}
-!30 = !{i16 undef, i32 1}
-!31 = !{i64 undef, i32 1}
-!32 = !{ptr  addrspace(5) undef, i32 1}
+!26 = !{half poison, i32 1}
+!27 = !{float poison, i32 1}
+!28 = !{double poison, i32 1}
+!29 = !{i8 poison, i32 1}
+!30 = !{i16 poison, i32 1}
+!31 = !{i64 poison, i32 1}
+!32 = !{ptr  addrspace(5) poison, i32 1}
 !50 = !{i32 1, i32 2, i32 3}
 !51 = !{!"int  addrspace(5)*", !"int  addrspace(5)*", !"int  addrspace(5)*"}
 !60 = !{i32 1, i32 1, i32 1}