[AIX][XCOFF] Fixed the test case which failed at aix OS because enable...

[AIX][XCOFF] Fixed the test case which failed at aix OS because enable -mignore-xcoff-visibility by default.

Summary:

because we enable -mignore-xcoff-visibility by default when there is no -fvisibility option in the clang in AIX OS
it will cause some test case fail at aix os. in order to let the -mignore-xcoff-visibility to be disable, we need to add the -fvisibility=default for those test case.

Reviewers: hubert.reinterpretcast daltenty
Differential Revision: https://reviews.llvm.org/D98660