deprecating types after colon

compiler/testData/diagnostics/testsWithStdLib/callableReference/function/extensionOnNullable.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS:-UNUSED_VARIABLE
+
 import kotlin.reflect.*
 
 class A {
@@ -6,5 +8,5 @@ class A {
 
 fun A?.foo() {}
 
-val f = A::foo : KMemberFunction0<A, Unit>
-val g = A?::foo : KExtensionFunction0<A, Unit>
+val f: KMemberFunction0<A, Unit> = A::foo
+val g: KExtensionFunction0<A, Unit> = A?::foo