First steps towards interprocedural analysis. Methods
(1) InvokeInstruction.resolveTargetMethod() and
(2) Frame.applyMethodSummary() introduced. At this point, (1)
always returns AlienMethod with its AlienSummary, and (2) only pops and
pushes the stack.
InvokeInstruction.getTargetMethod() commented out. This method is
expected to be needed later in a somewhat adapted way.