Export primitive flonum-denormalize as flo:ldexp and flo:scalbn.

Export primitive flonum-denormalize as flo:ldexp and flo:scalbn.

These are the familiar -- and when FLT_RADIX = 2, equivalent -- names
for the operation in libm.

`Denormalize' is not right: neither does it turn a normal number into
a subnormal, nor does it put anything into a canonical interval like
[1/2, 1) or [1, 2).  I personally favour `shift' -- it is, in Z, the
same as the bitwise shift operation.  But unless anyone else wants to
join me against this windmill I'll just stay with the familiar if
ugly libm names.