This patch adds a new off-thread delazification strategy, which adds a bit of
overhead to queue function with a priority order, which put the largest function
as the first functions to be delazified.
The intent of this new strategy is to limit the usage of main-thread
delazification to the smallest function, in case where the main-thread would win
the delazification race.
Differential Revision: https://phabricator.services.mozilla.com/D149651