ipa-pure-const.c (struct funct_state_d): Add can_free field.

	* ipa-pure-const.c (struct funct_state_d): Add can_free field.
	(varying_state): Add true for can_free.
	(check_call): For builtin or internal !nonfreeing_call_p set
	local->can_free.
	(check_stmt): For asm volatile and asm with "memory" set
	local->can_free.
	(analyze_function): Clear local->can_free initially, continue
	calling check_stmt until all flags are computed, dump can_free
	flag.
	(pure_const_write_summary): Write can_free flag.
	(pure_const_read_summary): Read it back.
	(propagate_pure_const): Propagate also can_free flag, set
	w->nonfreeing_fn if it is false after propagation.
	* cgraph.h (cgraph_node): Add nonfreeing_fn member.
	* gimple.c: Include ipa-ref.h, lto-streamer.h and cgraph.h.
	(nonfreeing_call_p): Return cgraph nonfreeing_fn flag if set.
	Also return true for IFN_ABNORMAL_DISPATCHER.
	* cgraph.c (cgraph_node::dump): Dump nonfreeing_fn flag.
	* lto-cgraph.c (lto_output_node): Write nonfreeing_fn flag.
	(input_overwrite_node): Read it back.

From-SVN: r217582