Add bounds check to StringImpl's operator[] for extra safety.
Created attachment 468310 [details] WIP Patch
Created attachment 468311 [details] WIP Patch
Created attachment 468312 [details] WIP Patch
Created attachment 468314 [details] WIP Patch
Created attachment 468322 [details] WIP Patch
<rdar://problem/117713370>
*** This bug has been marked as a duplicate of bug 263899 ***