bug: missing error (return code) for unknown fields #94

given

           EXEC SQL  FETCH SOMETHING INTO :FIELD END-EXEC.
      *
           IF SQLCODE = 0

resulted in

OCESQL*    EXEC SQL  FETCH SOMETHING INTO :FIELD END-EXEC.
OCESQL     CALL "OCESQLStartSQL"
OCESQL     END-CALL
      *
           IF SQLCODE = 0

The reason in this case was that FIELD was not contained in the variables visible to the parser (copybook instead of SQL INCLUDE, possibly because of missing support for #91).
The code generation should raise a clear error here "unknown bind variable :FIELD".

... rechecking the code - this happens here:

and there is indeed an output:

00234:E001:FIELD is not defined in the working-storage !

... but as ocesql still returns 0 and the message is placed to stdout this is easy to miss