(rationalize) works differently in ABCL

[Andrew Sengul]

I've been doing operations that require me to rationalize floats, and
I've found that (rationalize 2.3d0)gives very different output in ABCL
compared SBCL and CCL. Floats can have any number of valid rational
conversions but I'd expect a good algorithm for this conversion to find
23/10 rather than the huge numerators and denominators that get
produced. It appears that the (rationalize) in ABCL is using the same
algorithm as (rational) does in other CLs. Does (rationalize) just pass
through to (rational) in ABCL? Would it make sense for ABCL to adopt the
implementation of this function used by other CLs? Thanks.

Andrew