[NFC][tests][AIX] XFAIL test for lack of visibility support

[Jake-Egan]

Summary

With the addition of __attribute__((visibility("hidden"))) to the test, the test fails because AIX's current default behaviour is to ignore hidden visibility, so the expected error is not seen. This patch marks the test XFAIL on AIX for now.

[Jake-Egan]

Updated the comment.

[cebowleratibm]

The AIX default of ignoring source-level visibility is problematic. I agree the test should be xfailed for AIX.

You can put [NFC] and [tests] to the commit. Should be safe to commit.

[daltenty]

Resolved by https://reviews.llvm.org/D125141

clang/test/OpenMP/target_update_messages.cpp

+// Visibility hidden is not currently implemented on AIX.
+// XFAIL: aix
+
 // RUN: %clang_cc1 -verify=expected,lt50,lt51 -fopenmp -fopenmp-version=45 -ferror-limit 100 -o - -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,ge50,lt51 -fopenmp -fopenmp-version=50 -ferror-limit 100 -o - -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,ge50,ge51 -fopenmp -fopenmp-version=51 -ferror-limit 100 -o - -std=c++11 %s -Wuninitialized
 
 // RUN: %clang_cc1 -verify=expected,lt50,lt51 -fopenmp-simd -fopenmp-version=45 -ferror-limit 100 -o - -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,ge50,lt51 -fopenmp-simd -fopenmp-version=50 -ferror-limit 100 -o - -std=c++11 %s -Wuninitialized
 // RUN: %clang_cc1 -verify=expected,ge50,ge51 -fopenmp-simd -fopenmp-version=51 -ferror-limit 100 -o - -std=c++11 %s -Wuninitialized