Java: Fix issue with getting best type for model and make sure that lift always returns best candidate.

Author: michaelnebel

java/ql/src/utils/modelgenerator/internal/CaptureModelsSpecific.qll

@@ -74,13 +74,18 @@ class TargetApiSpecific extends Callable {
     isRelevantForModels(this)
   }
 
+  /** Gets a super implementation from source, if any. */
+  private Method getSuperImpl() {
+    exists(Method m | m = superImpl(this) and m.fromSource() | result = m)
+  }
+
   /**
-   * Gets the callable that a model will be lifted to, if any.
+   * Gets the callable that a model will be lifted to.
    */
   Callable lift() {
-    exists(Method m | m = superImpl(this) and m.fromSource() | result = m)
+    result = this.getSuperImpl()
     or
-    not exists(superImpl(this)) and result = this
+    not exists(this.getSuperImpl()) and result = this
   }
 }