EQUIVALENCE statements are not handled

[rtoy]

In general Fortran EQUIVALENCE statements aren't handled at all by f2cl, but there are cases where f2cl should be able to convert to Lisp.

If the EQUIVALENCE just aliases a bunch of variables and arrays together and they are all of the same basic type, f2cl should be able to create a giant array and map the variables and arrays at the appropriate locations in the array. F2cl cannot do that currently, except in some very simple cases.