Promises are enabled everywhere, and features are starting to depend on them (like STREAMS_API, for example). Also, after r186966 it is not necessary to disable promises with a runtime flag. Removing the JSC runtime flag for Symbols will come in a following patch.
This is reverting a large portion of https://bugs.webkit.org/show_bug.cgi?id=141965
Created attachment 257411 [details]
Comment on attachment 257411 [details]