This api is used in Workers on multiple threads. Therefore it shouldn't have a non-threadsafe structures in a static.
Created attachment 120108 [details] Patch
Just adding Eric and Kinuko as a fyi.
Comment on attachment 120108 [details] Patch The RegularExpression class does not look like threadsafe one... I only looked briefly though, but if you look and it is in fact threadsafe, please feel free to add some note and re-flip R?
*** This bug has been marked as a duplicate of bug 62813 ***