Minor code cleanup. These cases cannot occur.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13230 a5019735-40e9-0310-863c-91ae7b9d1cf9
Fix a few compiler warnings on Darwin.
Patch Guy Harris (guy@alum.mit.edu). Part of fixing BZ 312980.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13231 a5019735-40e9-0310-863c-91ae7b9d1cf9
Announce bug fix.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13232 a5019735-40e9-0310-863c-91ae7b9d1cf9