Added 0x0D to 2-byte opcode extension table for prefetch* variants
Fixed decode of existing 3dNow prefetchw instruction
Intel is scheduled to add a compatible prefetchw (same encoding) to future CPUs

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174920 91177308-0d34-0410-b5e6-96231b3b80d8