this patch tames down inliner on (mutiply) self-recursive always_inline functions.
While we already have caps on recursive inlning, the testcase combines early inliner
and late inliner to get very wide recursive inlining tree.  The basic idea is to
ignore DISREGARD_INLINE_LIMITS when deciding on inlining self recursive functions
(so we cut on function being large) and clear the flag once it is detected.

I did not include the testcase since it still produces a lot of code and would
slow down testing.  It also outputs many inlining failed messages that is not
very nice, but it is hard to detect self recursin cycles in full generality
when indirect calls and other tricks may happen.

gcc/ChangeLog:

	PR ipa/113291

	* ipa-inline.cc (enum can_inline_edge_by_limits_flags): New enum.
	(can_inline_edge_by_limits_p): Take flags instead of multiple bools; add flag
	for forcing inlinie limits.
	(can_early_inline_edge_p): Update.
	(want_inline_self_recursive_call_p): Update; use FORCE_LIMITS mode.
	(check_callers): Update.
	(update_caller_keys): Update.
	(update_callee_keys): Update.
	(recursive_inlining): Update.
	(add_new_edges_to_heap): Update.
	(speculation_useful_p): Update.
	(inline_small_functions): Clear DECL_DISREGARD_INLINE_LIMITS on self recursion.
	(flatten_function): Update.
	(inline_to_all_callers_1): Update.