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

compiler/testData/diagnostics/tests/thisAndSuper/superInExtensionFunctionCall.kt

@@ -1,6 +1,6 @@
 // No supertype at all
 class A1 {
     fun test() {
-        <!SUPER_IS_NOT_AN_EXPRESSION!>super<!>.equals(null) // Call to an extension function
+        <!SUPER_IS_NOT_AN_EXPRESSION!>super<!>.identityEquals(null) // Call to an extension function
     }
 }