[JSC] Add exception checks before and after viewWithUnderlyingString
Created attachment 403454 [details] Patch
<rdar://problem/65068473>
Win EWS is getting bad state (early failure without this patch)
Committed r263905: <https://trac.webkit.org/changeset/263905> All reviewed patches have been landed. Closing bug and clearing flags on attachment 403454 [details].