higher-order functions for traversing data structures. The higher-order
approach is too clumsy due to the lack of polymorphism and closures; you
have to use void* too much and it is more verbose than it should be.
Hence, I replaced all the uses of HT_first_match() and
HT_apply_to_all_nodes() with equivalent uses of the hashtable iterator.
Also replaced higher-order traversal functions for Memcheck's freed-list
and the thread stacks with iterators. That last change changes the
core/tool interface, so I've increased the version number.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@4415
fcdc60441e