rtl.def (REG): Remove middle field.

rtl.def (REG): Remove middle field.

gcc/
	* rtl.def (REG): Remove middle field.
	* rtl.h (rtx_def): Add orignal_regno to u2.
	(ORIGINAL_REGNO): Use it instead of field 1.
	(REG_ATTRS): Lower field index accordingly.
	* gengtype.c (adjust_field_rtx_def): Remove handling of
	ORIGINAL_REGNO.  Move REG_ATTRS index down.
	* print-rtl.c (print_rtx): Move ORIGINAL_REGNO handling to the
	code that prints the REGNO.

From-SVN: r210359