VfrCompiler used memcpy() on the overlapped buffer and caused data corruption. This commit replaces memcpy() with memmove() if the source or the destination buffer is not created in the function, so that the overlapped buffers can be copied correctly.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Gary Ching-Pang Lin <glin@suse.com>
Reviewed-by: Gao, Liming <liming.gao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2-buildtools/code/trunk/BaseTools@2646 c2973edb-eda0-4c78-bc6a-9341b269661f