Eliminate n_edges macro

	* basic-block.h (n_edges_for_function): Rename macro to...
	(n_edges_for_fn): ...this.
	(n_edges): Eliminate macro as work towards making uses of
	cfun be explicit.

	* cfg.c (init_flow): Update for renaming of "n_edges_for_function"
	to "n_edges_for_fn".

	* cfg.c (unchecked_make_edge): Remove usage of n_edges macro.
	(clear_edges): Likewise.
	(free_edge): Likewise.
	* cfghooks.c (dump_flow_info): Likewise.
	* cprop.c (is_too_expensive): Likewise.
	* df-core.c (df_worklist_dataflow_doublequeue): Likewise.
	* gcse.c (is_too_expensive): Likewise.
	(prune_insertions_deletions): Likewise.
	* mcf.c (create_fixup_graph): Likewise.
	* sched-rgn.c (haifa_find_rgns): Likewise.
	* tree-cfg.c (gimple_dump_cfg): Likewise.
	* var-tracking.c (variable_tracking_main_1): Likewise.

From-SVN: r205044