Followup to r14600. Copy the contents of pub_core_guest.h to pub_tool_guest.h
to make it available to tools. This allows to remove quite a bit of
ifdeffery from memcheck's mc_machine.c


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14601 a5019735-40e9-0310-863c-91ae7b9d1cf9