[NI] Fix not-null smartcast on intersection of nullable types

#KT-28670 Fixed

core/descriptors/src/org/jetbrains/kotlin/types/SpecialTypes.kt

@@ -81,8 +81,8 @@ class DefinitelyNotNullType private constructor(val original: SimpleType) : Dele
             }
         }
 
-        fun makesSenseToBeDefinitelyNotNull(type: UnwrappedType): Boolean =
-                type.canHaveUndefinedNullability() && !NullabilityChecker.isSubtypeOfAny(type)
+        private fun makesSenseToBeDefinitelyNotNull(type: UnwrappedType): Boolean =
+            type.canHaveUndefinedNullability() && !NullabilityChecker.isSubtypeOfAny(type)
     }
 
     override val delegate: SimpleType