Add test for obsolete issue

#KT-6502 Obsolete

idea/testData/checker/diagnosticsMessage/instantiationOfInnerClassInQualifiedForm.kt

@@ -0,0 +1,7 @@
+class A {
+    inner class XYZ
+
+    fun foo() {
+        val <warning>v</warning>: A.XYZ = A.<error descr="[RESOLUTION_TO_CLASSIFIER] Constructor of inner class XYZ can be called only with receiver of containing class">XYZ</error>()
+    }
+}