PR jit/63854: Fix leak of ipa hooks

PR jit/63854: Fix leak of ipa hooks

gcc/ChangeLog:
	PR jit/63854
	* ipa-prop.c (ipa_register_cgraph_hooks): Guard insertion of
	ipa_add_new_function on function_insertion_hook_holder being
	non-NULL.
	* ipa-reference.c (ipa_reference_c_finalize): Remove
	node_removal_hook_holder and node_duplication_hook_holder if
	they've been added to symtab.
	* toplev.c (toplev::finalize): Call ipa_reference_c_finalize
	before cgraph_c_finalize so that the former can access "symtab".

From-SVN: r218403