code: Add support for pmem non-temporal memcpy, memmove and memset

This pull request integrates the support for the PM versions of memset, memmove and memcpy using non-temporal instructions.
IMHO, calling `nodrain_movnt` in a loop for each 128 byte chunk is not a good idea. `nodrain_movnt` introduces some overhead with checking the input arguments, alignment, etc.
Also, what if `pmemdest` is not aligned? Current implementation will call `nodrain_movnt` for each 128B chunk (unaligned). So, in practice, it will fall into the slowest path, where the byte-by-byte copying takes place - standard memset() would be better in such case.
It would be better to inline a part of `nodrain_movnt` into this function, I suppose. Or simply copy over the whole `nodrain_movnt` code, and only replace src with some temporary buffer populated with `c` value.