fix: enable compilation with -skip-unused (workaround the interface bug in v.markused)

Author: spytheman

src/analyzer/psi/types/BaseType.v

@@ -5,6 +5,7 @@ pub:
 	module_name string
 }
 
+@[markused]
 pub fn (s &BaseType) module_name() string {
 	return s.module_name
 }