Fix SCC discovery in ipa-modref

Fix SCC discovery in ipa-modref

this patch fixes SCC discovery in ipa-modref which is causing misoptimization
of gnat bootstrapped with LTO, PGO and -O3.

I also improved debug info and spotted wrong parameter to ignore_stores_p
(which is probably quite harmless since we only inline matching functions, but
it is better to be consistent).

	PR bootstrap/97350
	* ipa-modref.c (ignore_edge): Do not ignore inlined edes.
	(ipa_merge_modref_summary_after_inlining): Improve debug output and
	fix parameter of ignore_stores_p.