* gcse.c (post_dominators): Kill.
(alloc_code_hoist_mem, free_code_hoist_mem); Kill post_dominators.
(compute_code_hoist_data): Use compute_flow_dominators. Do not
pass in a pdom array since we do not need pdoms.
* haifa-sched.c (schedule_insns): Similarly.
* flow.c (compute_dominators): Remove dead function.
(compute_flow_dominators): Do not compute doms or pdoms if the
caller does not request them. Split up loop to build doms and
pdoms. Use a worklist to compute doms and pdoms.
* basic-block.h (compute_dominators): Remove prototype.