Construct ipa_reduced_postorder always for overwritable (PR ipa/89009).

Construct ipa_reduced_postorder always for overwritable (PR ipa/89009).

2019-02-11  Martin Liska  <mliska@suse.cz>

	PR ipa/89009
	* ipa-cp.c (build_toporder_info): Remove usage of a param.
	* ipa-inline.c (inline_small_functions): Likewise.
	* ipa-pure-const.c (propagate_pure_const): Likewise.
	(propagate_nothrow): Likewise.
	* ipa-reference.c (propagate): Likewise.
	* ipa-utils.c (struct searchc_env): Remove unused field.
	(searchc): Always search across AVAIL_INTERPOSABLE.
	(ipa_reduced_postorder): Always allow AVAIL_INTERPOSABLE as
	the only called IPA pure const can properly not propagate
	across interposable boundary.
	* ipa-utils.h (ipa_reduced_postorder): Remove param.
2019-02-11  Martin Liska  <mliska@suse.cz>

	PR ipa/89009
	* g++.dg/ipa/pr89009.C: New test.

From-SVN: r268762