[Ecls-list] Getting a bool into C from a cl_object

[Erik Winkels]

What's the best way to turn a cl_object into an ECL bool in C?

Currently I'm doing:

    bool acw = ecl_eql(auto_create_window, Ct);

Where auto_create_window is a cl_object that's either set to NIL or T.

The above is error prone however when the cl_object can be NIL or something
else.