** (FLOAT X) for X of type DOUBLE-FLOAT now returns X in all
circumstances.
** optimizer for (EXPT X 0) did not work for X not of type FLOAT.
+ ** (GCD 0 <negative-integer>) returned <negative-integer>.
+ ** LCM should return a non-negative integer.
planned incompatible changes in 0.8.x:
* (not done yet, but planned:) When the profiling interface settles