attribs.c: New file, from c-common.c.

	* attribs.c: New file, from c-common.c.
	(attribute_tables): Now four elements.
	(format_attribute_table, lang_attribute_common): New variables.
	(init_attributes): Reflect above changes.
	(handle_mode_attribute): Delete check for wider than uintmax.
	* c-common.c: Delete parts moved to attribs.c.
	(enum attrs): Deleted; unused.
	(c_format_attribute_table): New variable.
	(c_common_lang_init): Initialize format_attribute_table with it.
	* c-common.h (decl_attributes): Remove decl.
	* tree.h (decl_attribute): Move it to here.
	* Makefile.in (C_AND_OBJS_OBJS): Add attribs.o.
	(attribs.o): New rule.

From-SVN: r45753