postcall_hook markers surround IR instructions containing calls to opaque functions (
registers_clobbered) which are used to say which register variables were clobbered by the original callee. All calls have attribute
opaque_true function call is used to prevent DCE (we make all branch conditions opaque).
In the process of testing
tac coreutil binary, for a specific functions we have the following BBs (only relevant parts are included):
; *** IR Dump After Simplify the CFG ***