746838 - Load jsreftests metadata in the background

Status: NEW

(Core :: JavaScript Engine, defect)

Description

[Terrence Cole [:terrence]]

Naturally, this cannot use threads -- we will be forking in the foreground -- but multiprocessing should be an adequate drop in replacement.  If it is not available (e.g. python2.5 on some build boxes) then we can just fall back to current behavior and load them in a single step.

The hard part here is going to be ensuring that we only iterate the list of test we get back from load function once, since it will be a generator and not a list.