switch global null to come from Nullable module and not Null (#88)

* switch global null to come from Nullable module and not Null

* changelog

Author: zth

CHANGELOG.md

@@ -23,6 +23,7 @@
 - Remove `reduceReverse` in favor of `reduceRight`. https://github.com/rescript-association/rescript-core/pull/49
 - Fixed type signatures of `reduce` and `reduceWithIndex`. https://github.com/rescript-association/rescript-core/pull/49
 - Add `panic`/`Error.panic`. https://github.com/rescript-association/rescript-core/pull/72
+- The globally available `null` value now originates from `Nullable` and not `Null`, just like the globally available `undefined` value does. https://github.com/rescript-association/rescript-core/pull/88
 
 ### Documentation
 

src/RescriptCore.res

@@ -47,7 +47,7 @@ module Intl = Core__Intl
 @val external document: Dom.document = "document"
 @val external globalThis: {..} = "globalThis"
 
-external null: Core__Null.t<'a> = "#null"
+external null: Core__Nullable.t<'a> = "#null"
 external undefined: Core__Nullable.t<'a> = "#undefined"
 external typeof: 'a => Core__Type.t = "#typeof"