Move JSC/runtime/StringConcatenate to wtf/text, make it work for Strings too. Add a special JSC/runtime/UStringConcatenate class that inherits from StringConcatenate, and extends it for UString.
Exactly the same design that has been done while refactoring StringBuilder.
The UString variants can all be removed as soon as WTF::String & JSC::UString converge.
Created attachment 70594 [details]
Please wait for EWS before reviewing.
Created attachment 70596 [details]
I ran svn-create-patch from within JSC, maybe that's why the bots can't apply the patch?
Comment on attachment 70596 [details]
Landed in r69663.