* final.c (cleanup_subreg_operands): New function.
        (final_scan_insn): Use it.
        (alter_subreg): Clear the "used" field when we turn a SUBREG into
        a REG.
        * reload1.c (reload): Delete CLOBBER insns and also cleanup SUBREG
        operands when reload has finished.
        * reload.h (cleanup_subreg_operands): Declare..
        * flow.c (life_analysis_1): No longer delete CLOBBER insns after
        reload.  Handled in reload itself.
Should fix sh, sparc and probably other problems with post-reload life pass
and scheduling interactions.

From-SVN: r23377