target/riscv: Add helper functions to calculate current number of masked bits for pointer masking Signed-off-by: Alexey Baturo <baturo.alexey@gmail.com> Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-ID: <20250106102346.1100149-4-baturo.alexey@gmail.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>