Covert ipa-pure-const.c to symbol_summary.

Covert ipa-pure-const.c to symbol_summary.

2018-06-08  Martin Liska  <mliska@suse.cz>

	* ipa-pure-const.c (struct funct_state_d): Do it class instead
	of struct.
	(class funct_state_summary_t): New function_summary class.
	(has_function_state): Remove.
	(get_function_state): Likewise.
	(set_function_state): Likewise.
	(add_new_function): Likewise.
	(funct_state_summary_t::insert): New function.
	(duplicate_node_data): Remove.
	(remove_node_data): Remove.
	(funct_state_summary_t::duplicate): New function.
	(register_hooks): Create new funct_state_summaries.
	(pure_const_generate_summary): Use it.
	(pure_const_write_summary): Likewise.
	(pure_const_read_summary): Likewise.
	(propagate_pure_const): Likewise.
	(propagate_nothrow): Likewise.
	(dump_malloc_lattice): Likewise.
	(propagate_malloc): Likewise.
	(execute): Do not register hooks, just remove summary
	instead.
	(pass_ipa_pure_const::pass_ipa_pure_const): Simplify
	constructor.

From-SVN: r261313