The former just checks that the given block is valid by checking
the header and footer.
The later sets the memory block's tag. With extra debug code, we
can use that for monitoring/checking particular allocations.
Reviewed-by: José Fonseca <jfonseca@vmware.com>
Add a DEBUG_FREED_MEMORY option to help catch use-after-free errors.
Add debug_memory_check() function which can be periodically called to
check that all known blocks are good.
Reviewed-by: José Fonseca <jfonseca@vmware.com>
