We don't have sufficient registers to keep both in registers, and DFG JIT will trample esi; it doesn't matter if the bucketCount gets stomped on (in fact it may add to randomness!), but it if the timeoutCheck gets trashed we may make calls out to the timout_check stub function too frequently (regressing performance). This patch has no perf impact on sunspider.
Created attachment 109543 [details] Fix
Comment on attachment 109543 [details] Fix r=me
Fixed in r96563