Come up with memop_ret enum instead of int endp for memory operations.

Come up with memop_ret enum instead of int endp for memory operations.

2018-11-27  Martin Liska  <mliska@suse.cz>

	* asan.c (asan_emit_stack_protection): Use new enum values
	instead of int constants.
	* builtins.c (expand_builtin_memory_copy_args): Replace int
	type with memop_ret enum type.
	(expand_builtin_mempcpy_args): Likewise.
	(expand_builtin_memcpy): Use new enum values
	instead of int constants. Likewise.
	(expand_builtin_mempcpy): Likewise.
	(expand_movstr): Likewise.
	(expand_builtin_strcpy_args): Likewise.
	(expand_builtin_stpcpy_1): Likewise.
	(expand_builtin_strncpy): Likewise.
	(expand_builtin_memset_args): Likewise.
	* expr.c (move_by_pieces_d::finish_endp): Rename to ...
	(move_by_pieces_d::finish_retmode): ... this.
	(move_by_pieces): Change last argument type to memop_ret.
	(store_by_pieces): Use new enum values
	instead of int constants.
	(emit_block_move_hints): Likewise.
	(emit_push_insn): Likewise.
	(store_expr): Likewise.
	* expr.h (store_by_pieces): Change int to newly added enum
	type.
	* rtl.h (enum memop_ret): Define.
	(move_by_pieces): Use the enum type.

From-SVN: r266508