[AIX][XCOFF] created a test case to verify the raw text section of xcoffobject file

SUMMARY:
in the patch https://reviews.llvm.org/D66969 . we need a test case to verify the out text section of the xcoffobject file is correct or not.

but we do not have llvm disassembly tools to dump the xcoffobjectfile . since we commit the patch https://reviews.llvm.org/D70255, we have tools for it. we create this test case for it.

Reviewers: daltenty,hubert.reinterpretcast,

Differential Revision: https://reviews.llvm.org/D70719