* gcse.c (run_jump_opt_after_gcse): New variable.
        (gcse_main): Returns an integer.
        (hash_scan_set): Record initializations from CONST_DOUBLEs too.
        (try_replace_reg): Update some comments.
        (cprop_insn): Allow propagation into some JUMP_INSNs too.
        * rtl.h (gcse_main): Update prototype.
        * toplev.c (rest_of_compilation): If gcse_main returns nonzero,
        then run a jump optimization pass.
        * jump.c (delete_barrier_successors): Delete nop jumps too.

From-SVN: r25673