[MC] Convert other MachO tests from macho-dump to llvm-readobj.

This commit accomplish two goals:
1) it's a step forward to deprecate macho-dump, now less than 40 tests
rely on it.

2) It tests all the MachO specific features introduced in llvm-readobj in
the following commits:  r246789, r246665, r246474.

While the conversion is mostly mechanical (I double-checked all the
tests output one by one, but still), a post-commit review is greatly
appreciated.

llvm-svn: 246904