Improve the performance of memcpy and memmove

The performance of memcpy and memmove of the general version is very inefficient, this patch improved them.

Change-Id: Id3e3d4bae07fedccb0fb97ac916dcb0897b128b7
Signed-off-by: Miao Xie <miaox <at> cn.fujitsu.com>
Improve memcopy/memmove

Thanks to DerTeufel!

Change-Id: Ie549325afdb82a9ba265c6804e72778cf6bb51de