BaseMemoryLib has recently been extended with an API function IsZeroBuffer(), so copy the default implementation into BaseMemoryLibStm as well. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>