1.1.14: will be tagged as "sbcl-1.1.14"
Micro-optimize vector creation.

transform-make-array-vector expanded into
(allocate-vector typecode (the index length) (ceiling length x))
but the transform applied to CEILING before it was known that LENGTH
is of type INDEX was producing bad results,
(ceiling (truly-the index length) x) solves that.
Optimize CONCATENATE transform.

Avoid redundant type-checks, avoid passing unnecessary arguments to
REPLACE.