Delete Hashable, pull up its members to Any

Extensions on nullable types remain in Library.kt

 #KT-1741 Obsolete
 #KT-2805 Obsolete
 #KT-1365 Fixed
 #KT-4517 In Progress

idea/testData/completion/basic/common/InExpressionNoPrefix.kt

@@ -4,6 +4,5 @@ class Test {
     }
 }
 
-// EXIST: Any, Nothing, Unit, Int, Number
-// EXIST: Array, Hashable
+// EXIST: Any, Nothing, Unit, Int, Number, Array
 // EXIST_JAVA_ONLY: Math, Thread