add AVX512 optimized memcpy
add AVX512 optimized memcpy

stlankes/HermitCore,RWTH-OS/HermitCore,RWTH-OS/HermitCore,stlankes/HermitCore,stlankes/HermitCore,RWTH-OS/HermitCore,RWTH-OS/HermitCore,stlankes/HermitCore,RWTH-OS/HermitCore,stlankes/HermitCore,RWTH-OS/HermitCore,stlankes/HermitCore