Make mempcpy more optimal (PR middle-end/70140).

Make mempcpy more optimal (PR middle-end/70140).

2017-08-01  Martin Liska  <mliska@suse.cz>

	PR middle-end/70140
	* gcc.dg/string-opt-1.c: Adjust test-case to scan for memcpy.
2017-08-01  Martin Liska  <mliska@suse.cz>

	PR middle-end/70140
	* builtins.c (expand_builtin_memcpy_args): Remove.
	(expand_builtin_memcpy): Call newly added function
	expand_builtin_memory_copy_args.
	(expand_builtin_memcpy_with_bounds): Likewise.
	(expand_builtin_mempcpy): Remove last argument.
	(expand_builtin_mempcpy_with_bounds): Likewise.
	(expand_builtin_memory_copy_args): New function created from
	expand_builtin_mempcpy_args with small modifications.
	(expand_builtin_mempcpy_args): Remove.
	(expand_builtin_stpcpy): Remove unused argument.
	(expand_builtin): Likewise.
	(expand_builtin_with_bounds): Likewise.

From-SVN: r250771