[FIR-TEST] Add new testdata generated after changes in previous commit

compiler/testData/diagnostics/tests/inner/nestedClassExtendsOuterGeneric.fir.kt

@@ -0,0 +1,12 @@
+open class Outer<T> {
+    class Nested<U> : Outer<U>() {
+        fun bar(): U = foo()
+        fun baz(): U = super.foo()
+    }
+    class Nested2 : Outer<String>() {
+        fun bar(): String = foo()
+        fun baz(): String = super.foo()
+    }
+    
+    fun foo(): T = null!!
+}