Release cgraph_{node,edge} via ggc_free (PR ipa/89330).

Release cgraph_{node,edge} via ggc_free (PR ipa/89330).

2019-07-28  Martin Liska  <mliska@suse.cz>

	PR ipa/89330
	* cgraph.c (symbol_table::create_edge): Always allocate
	a cgraph_edge.
	(symbol_table::free_edge): Store summary_id to
	edge_released_summary_ids if != -1;
	* cgraph.h (NEXT_FREE_NODE): Remove.
	(SET_NEXT_FREE_NODE): Likewise.
	(NEXT_FREE_EDGE): Likewise.
	(symbol_table::release_symbol): Store summary_id to
	cgraph_released_summary_ids if != -1;
	(symbol_table::allocate_cgraph_symbol): Always allocate
	a cgraph_node.

From-SVN: r273857