re PR target/54640 (arm_adjust_block_mem: signed/unsigned comparison [-Werror=sign-compare])

        PR target/54640
        * config/arm/arm.c (const_ok_for_dimode_op): Make code consistent
        for HOST_WIDE_INT of 32 bit / same size as int.
        (arm_block_move_unaligned_straight): Likewise.
        (arm_adjust_block_mem): Likewise.

From-SVN: r196290