fwprop.c (forward_propagate_and_simplify): Only attach a REG_EQUAL note to an insn if the destination is a register.

        * fwprop.c (forward_propagate_and_simplify): Only attach a
        REG_EQUAL note to an insn if the destination is a register.
        * gcse.c (try_replace_reg): Likewise.

        testsuite/
        * gnat.dg/memtrap.adb: New test.

From-SVN: r164245