Fix bcopy() to allow memory area overlap

Under Solaris bcopy() allows overlapping memory areas so we
must use memmove() instead of memcpy().

Signed-off-by: Ricardo M. Correia <ricardo.correia@oracle.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

include/sys/sysmacros.h

@@ -110,7 +110,7 @@
 /* Map some simple functions.
  */
 #define bzero(ptr,size)			memset(ptr,0,size)
-#define bcopy(src,dest,size)		memcpy(dest,src,size)
+#define bcopy(src,dest,size)		memmove(dest,src,size)
 #define bcmp(src,dest,size)		memcmp((src), (dest), (size_t)(size))
 
 /* Dtrace probes do not exist in the linux kernel */