A pass which segregates direct stack accesses from all other
memory accesses through appropriate alias information metadata.
By doing so, we provide a way to say that stack accesses reasonably
do not interfere with any other memory access. This pass also tries
to canonicalize `inttoptr` + `add` instructions into `getelementptr`s
so as to avoid the use of `inttoptr`, which would otherwise inhibit
compiler optimizations.
Antonio Frighetto