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
	* tree.c (fld_decl_context): Break out from ...
	(free_lang_data_in_decl): ... here; free TREE_PUBLIC, TREE_PRIVATE
	DECL_ARTIFICIAL of TYPE_DECL; do not free TREE_TYPE of TYPE_DECL.
	(fld_incomplete_type_of): Build copy of TYP_DECL.
	* ipa-devirt.c (free_enum_values): Rename to ...
	(free_odr_warning_data): ... this one; free also duplicated TYPE_DECLs
	and TREE_TYPEs of TYPE_DECLs.
	(get_odr_type): Initialize odr_vtable_hash if needed.

From-SVN: r266350