On AIX we don’t have .debug_addr section. (llvm#96935)

According to Zheng @chenzheng1030, there is no .debug_addr section on
AIX.
Due to its absence on AIX, the test case may produce inconsistent
results, either passing or failing. This PR ensures that the test case
is marked as not applicable for AIX.

llvm/test/DebugInfo/attr-btf_type_tag.ll

@@ -1,4 +1,4 @@
-; XFAIL: target={{.*}}-aix{{.*}}
+; UNSUPPORTED: target={{.*}}-aix{{.*}}
 ; REQUIRES: object-emission
 ; RUN: llc -filetype=obj -o %t %s
 ; RUN: llvm-dwarfdump -debug-info %t | FileCheck %s