re PR ipa/87957 (ICE tree check: expected tree that contains ‘decl minimal’ structure...

re PR ipa/87957 (ICE tree check: expected tree that contains ‘decl minimal’ structure, have ‘identifier_node’ in warn_odr, at ipa-devirt.c:1051 since r265519)

	PR lto/87957
	* ipa-devirt.c (odr_subtypes_equivalent_p): Report ODR violation
	when sybtype already violates ODR.
	(get_odr_type): Do not ICE when insert is false and type duplicate
	is not registered yet.
	(register_odr_type): Be sure to register subtypes first.

From-SVN: r266322