[PSI, FE, PSI2IR] Use labels for referencing specific receiver

compiler/testData/diagnostics/tests/extensions/contextReceivers/superWithContext.fir.kt

@@ -0,0 +1,19 @@
+interface Context {
+    fun h() {}
+}
+
+open class A {
+    open fun f() {}
+}
+
+class B : A() {
+    override fun f() {}
+
+    context(Context)
+    inner class C {
+        fun g() {
+            super@B.f()
+            super@Context.<!UNRESOLVED_REFERENCE!>h<!>()
+        }
+    }
+}