[jnigen] Fix generic subinterfaces not specifying full type params (#2255)

Classes that inherited a generic without specifying all type parameters were not generated. Filling the ones not specified with `JObject?`.

Author: HosseinYousefi

pkgs/jnigen/CHANGELOG.md

@@ -9,6 +9,9 @@
   instead of `build.gradle`.
 - Fixed a bug where Kotlin suspend functions that returned nullable values were
   generated incorrectly.
+- Fixed a [bug](https://github.com/dart-lang/native/issues/2250) where classes
+  that inherited a generic without specifying all type parameters were not
+  generated.
 
 ## 0.14.1
 

pkgs/jnigen/lib/src/bindings/linker.dart

@@ -423,6 +423,9 @@ class _TypeMover extends TypeVisitor<void> {
       final index = fromType.classDecl.allTypeParams
           .indexWhere((typeParam) => typeParam.name == typeVar.name);
       if (index != -1) {
+        if (index >= fromType.params.length) {
+          return DeclaredType.object.clone();
+        }
         return fromType.params[index].clone(until: GenerationStage.linker);
       }
     }