[cmucl-imp] Snapshot 2018-01

[Raymond Toy]

The new year brings us a new snapshot for January.  A few minor
changes:

* ASDF upgraded to 3.3.1
* A new random number generator where mt19937 is replaced by
  xoroshiro128+.  This generator is faster than mt19937 and instead of
  some 600 words of state, only 4 are needed.

The new generator requires a cross-compile using
21c/boot-21c-cross.lisp.

Binaries will be uploaded soon.

--
Ray