Merge r6132:

Merge r6132:

Minor changes for redirection on AIX.  The only significant change is
that it now checks for, warns about and disallows, attempts to
redirect to, or wrap with, a function for which no TOC pointer can be
found, since that would be really asking for trouble (a segfault).

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@6269