deprecating types after colon

compiler/testData/diagnostics/tests/dataFlowInfoTraversal/MultiDeclaration.kt

@@ -1,7 +1,9 @@
+// !CHECK_TYPE
+
 fun Int.component1() = "a"
 
 fun foo(a: Number) {
     val (x) = a as Int
-    <!DEBUG_INFO_SMARTCAST!>a<!> : Int
-    x : String
+    checkSubtype<Int>(<!DEBUG_INFO_SMARTCAST!>a<!>)
+    checkSubtype<String>(x)
 }