Add ClassBuilderMode.KAPT3 tests

compiler/testData/codegen/kapt/innerClasses.kt

@@ -0,0 +1,26 @@
+// WITH_RUNTIME
+
+package test
+
+class TopLevel {
+    companion object {
+        fun a() {}
+
+        @JvmStatic
+        val q = "A"
+    }
+
+    fun b() {}
+
+    val x: String
+
+    val y = 5
+
+    class NestedClass {
+        inner class NestedInnerClass
+    }
+
+    object InnerObject
+
+    interface InnerInterface
+}