Some tests for override action has been added.

idea/testData/codeInsight/overrideImplement/traitGenericImplement.kt

@@ -0,0 +1,7 @@
+trait G<T> {
+    fun foo(t : T) : T
+}
+
+class GC<T>() : G<T> {
+    <caret>
+}