[MERGE #3725 @obastemur] xplat: improve virtual memory region lookups
[MERGE #3725 @obastemur] xplat: improve virtual memory region lookups

Merge pull request #3725 from obastemur:exp_prop_in

virtual memory region linked list reaches to ~400 items during AcmeAir
warmup and successful lookups are mostly around the last found item.

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