Unbreak the MacOS port following the recent ppc64le port merge.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14266 a5019735-40e9-0310-863c-91ae7b9d1cf9
Fix some comments


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14267 a5019735-40e9-0310-863c-91ae7b9d1cf9
Remove benign macro redefinition.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14269 a5019735-40e9-0310-863c-91ae7b9d1cf9