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

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

@@ -0,0 +1,26 @@
+// !LANGUAGE: -NestedClassesInEnumEntryShouldBeInner
+
+class A {
+    inner class B {
+        class C
+    }
+    
+    fun foo() {
+        class B {
+            class C
+        }
+    }
+}
+
+fun foo() {
+    class B {
+        class C
+    }
+}
+
+
+enum class E {
+    E1 {
+        class D
+    }
+}