deprecating types after colon

idea/testData/checker/QualifiedThisInClosures.kt

@@ -1,16 +1,18 @@
-    class A(val a:Int) {
+fun <T> checkSubtype(t: T) = t
+
+class A(val a:Int) {
 
       inner class B() {
-        val x = this@B : B
-        val y = this@A : A
-        val z = this : B
-        val Int.xx : Int get() = this : Int
+        val x = checkSubtype<B>(this@B)
+        val y = checkSubtype<A>(this@A)
+        val z = checkSubtype<B>(this)
+        val Int.xx : Int get() = checkSubtype<Int>(this)
         fun Char.xx() : Double.() -> Unit {
-          this : Char
-          val <warning>a</warning>: Double.() -> Unit = { this : Double + this@xx : Char}
-          val <warning>b</warning>: Double.() -> Unit = a@{this@a : Double + this@xx : Char}
-          val <warning>c</warning> = a@{<error>this@a</error> <error>+</error> this@xx : Char}
-          return (a@{this@a : Double + this@xx : Char})
+          checkSubtype<Char>(this)
+          val <warning>a</warning>: Double.() -> Unit = { checkSubtype<Double>(this) + checkSubtype<Char>(this@xx) }
+          val <warning>b</warning>: Double.() -> Unit = a@{checkSubtype<Double>(this@a) + checkSubtype<Char>(this@xx) }
+          val <warning>c</warning> = a@{<error>this@a</error> <error>+</error> checkSubtype<Char>(this@xx) }
+          return (a@{checkSubtype<Double>(this@a) + checkSubtype<Char>(this@xx) })
         }
       }
     }