ssa-dce.c (EXECUTE_IF_UNNECESSARY): Verify INSN is an INSN_P before checking to see if it is dead.

       * ssa-dce.c (EXECUTE_IF_UNNECESSARY): Verify INSN is an
        INSN_P before checking to see if it is dead.
        (mark_all_insn_unnecessary): Similarly.
        (ssa_eliminate_dead_code): Similarly.
        * rtl.h (struct rtx_def): Update comments for in_struct usage
        in dead code elimination pass.
        (INSN_DEAD_CODE_P): Allow JUMP_INSN and CALL_INSN as well.

From-SVN: r60520