* gdbarch.sh (overlay_update): New gdbarch function.

	* gdbarch.sh (overlay_update): New gdbarch function.
	(struct obj_section): Add forward declaration.
	* gdbarch.c, gdbarch.h: Regenerate.

	* symfile.c (simple_overlay_update): Make global.
	(target_overlay_update): Remove variable.
	(overlay_is_mapped): Call gdbarch_overlay_update instead of
	target_overlay_update.
	(overlay_load_command): Likewise.
	* symfile.h (struct obj_section): Add forward declaration.
	(simple_overlay_update): Add prototype.

	* m32r-tdep.c (m32r_gdbarch_init): Install simple_overlay_update.