Kapt: Add runtime library, move all modules inside the 'kapt3' directory

plugins/kapt3/kapt3-compiler/testData/converter/defaultImpls.kt

@@ -0,0 +1,15 @@
+interface IntfWithoutDefaultImpls
+
+interface IntfWithDefaultImpls {
+    fun a() {}
+}
+
+interface Intf {
+    companion object {
+        val BLACK = 1
+        const val WHITE = 2
+    }
+
+    val color: Int
+        get() = BLACK
+}