Ref https://github.com/tc39/test262/pull/1711#issuecomment-419973158

Import test changes from JavaScriptCore

[javascriptcore-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: 873fa026de targetRevisionAtLastExport: 92b6974d

[javascriptcore-test262-automation] Changes from https://github.com/webkit/webkit.git at sha 873fa026de on Sat Sep 08 2018 18:19:30 GMT+0000 (Coordinated Universal Time)

Intl: Add tests for subclassing Locale, ListFormat and RelativeTimeFormat.

Import test changes from JavaScriptCore

[javascriptcore-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: a2f7b0c562 targetRevisionAtLastExport: 5594c916

[javascriptcore-test262-automation] Changes from https://github.com/webkit/webkit.git at sha a2f7b0c562 on Fri Sep 07 2018 18:19:35 GMT+0000 (Coordinated Universal Time)

Fixes #1705.

Import test changes from JavaScriptCore

[javascriptcore-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: 3ced8564a6 targetRevisionAtLastExport: f8c62a49

[javascriptcore-test262-automation] Changes from https://github.com/webkit/webkit.git at sha 3ced8564a6 on Thu Sep 06 2018 18:18:56 GMT+0000 (Coordinated Universal Time)