fix: always ensure K&R functions have at least 1 declaration

[amaanq]

• Closes Query with supertype fails when it shouldn't #245

Problem

Functions with empty parameters are getting parsed internally as _old_style_function_definition, causing seemingly-correct queries to fail.

Solution

For "old-style" K&R functions, there should be at least 1 declaration following the declarator, no declarators should parse as a normal function_definition