PR optimization/12628
	* toplev.c (rest_of_handle_jump_bypass): Call reg_scan.
	* regclass.c (reg_scan): Include allocate_reg_info time in
	TV_REG_SCAN.  Minor clean-ups.
	(reg_scan_update): Minor clean-ups.

	* gcc.dg/20031201-1.c: New test case.

From-SVN: r74125