Keep track of second receiver type in CallReceiver

#KT-17725 Fixed Target versions 1.1.5

compiler/testData/codegen/box/smartCasts/kt17725.kt

@@ -0,0 +1,10 @@
+class Bob {
+    fun Bob.bar() = "OK"
+}
+
+fun Any.foo() = when(this) {
+    is Bob -> bar()
+    else -> throw AssertionError()
+}
+
+fun box(): String = Bob().foo()