[MERGE #631] Temporary memop fix for breaking sites
[MERGE #631] Temporary memop fix for breaking sites

Merge pull request #631 from pleath:soducc
Removal of some overly conservative code in mem op preparation exposed a bug in induction variable analysis. We can select the wrong value as the upper bound of a loop, which can lead us to perform a memcopy with the wrong number of elements. On some popular sites this caused massive array growth, with hangs and memory spikes. Restoring the deleted code as a short-term fix while investigation of the deeper issue continues.

Microsoft/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore,mrkmarron/ChakraCore,mrkmarron/ChakraCore,mrkmarron/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore,Microsoft/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore