PR ipa/67056
	* ipa-polymorphic-call.c (possible_placement_new): If cur_offset
	is negative we don't know the type.
	(check_stmt_for_type_change): Skip constructors of non-polymorphic
	types as those won't help devirutalization.
	* g++.dg/ipa/pr67056.C: New testcase.

From-SVN: r229148