SetLocals to temporaries will only be generated if they are used within other blocks, due to the SSA based DCE.
Created attachment 90864 [details] The patch
Comment on attachment 90864 [details] The patch r=me
Attachment 90864 [details] did not pass style-queue: Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/JavaScriptCore/ChangeLog', u'Source..." exit_code: 1 Source/JavaScriptCore/ChangeLog:1: ChangeLog entry has no bug number [changelog/bugnumber] [5] Total errors found: 1 in 3 files If any of these errors are false positives, please file a bug against check-webkit-style.
fixed in r84748