Change:
Add loopF to terminate a roller when it exits the function that contains
the target loop;
Implement FIFO with map and list, implement rollerStateStack as a FIFO;
Move roller code into transferToBasicBlock;

Fix:
getTargetFunction, used by pthread_create, is unable to find
non-constant function targets; previously -O2 inclines create_worker so
the function target is constant; however -O2 removes [[loop_target]]; so
ultimately I manually inlined create_worker and disabled -O2