Include pub_core/tool_clreq.h instead of valgrind.h where apropriate.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13555 a5019735-40e9-0310-863c-91ae7b9d1cf9
VG_(memset) cannot handle NULL pointers and needs to be guarded.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13556 a5019735-40e9-0310-863c-91ae7b9d1cf9