[asan] Support for %z to Printf()

At the moment, asan internal Printf() uses %l modifier for printing
values of size_t and related types. This works, because we control
both the implementation of Printf and all its uses, but can be a
little misleading.

This change adds support for %z to Printf(). All callers that print
sizes and pointers as integers are switched to %zu / %zx.

llvm-svn: 153177