After investigating CI issues on AIX, I can't explain to myself why this is happening and it looks like a potential compiler bug. XFAILing the AIX test for now until this can be investigated.

Author: ldionne

libcxx/test/libcxx/clang_modules_include.gen.py

@@ -49,6 +49,9 @@
 // TODO: Investigate why this doesn't work on Picolibc once the locale base API is refactored
 // UNSUPPORTED: LIBCXX-PICOLIBC-FIXME
 
+// TODO: Fix seemingly circular inclusion or <wchar.h> on AIX
+// UNSUPPORTED: LIBCXX-AIX-FIXME
+
 {lit_header_restrictions.get(header, '')}
 {lit_header_undeprecations.get(header, '')}
 
@@ -83,6 +86,9 @@
 // TODO: Investigate why this doesn't work on Picolibc once the locale base API is refactored
 // UNSUPPORTED: LIBCXX-PICOLIBC-FIXME
 
+// TODO: Fix seemingly circular inclusion or <wchar.h> on AIX
+// UNSUPPORTED: LIBCXX-AIX-FIXME
+
 @import std;
 
 """