* gcse.c (hash_scan_set): If cprop, see if REG_EQUAL or REG_EQUIV.
Don't CSE a nop.
(hash_scan_insn): Clean up calls to hash_scan_set.
(compute_kill_rd): REGNO now unsigned.
(try_replace_reg): Rework to use simplify_replace_rtx.
(cprop_jump, cprop_cc0_jump): Likewise.
(cprop_insn): Call find_reg_equal_equiv_note.
Reflect changes to cprop_jump and cprop_cc0_jump.
From-SVN: r39774
