Handle flags as instrumentation to compute hash chain uses xor.
Also add code to handle red zone for leaf functions

Building CFGs seems to require that the assembly is correct
Force building of the assembly after making mods to the IR
and before building a new CFG

updated zafl.sh with better help screen, debugged zax-base to properly implement domgraph optimziation

filter entry block if has exactly 1 successor
filter exit blocks if have exactly 1 predecessor

Before eliding conditional branch,  verify that neither successor is IBTA