Rewrite benchmark harnesses to use one JS process per benchmark.

Avoids the need for the module pattern (which may have impacted results,
and didn't play nice with pdf.js anyway).

Also avoids GC striking randomly, penalizing random benchmarks.

Results are slightly different than before, but should be more accurate
and reliable.
Add pdf.js benchmark.
Browser and xpcshell profiler don't have the exact same format.
Allow URIs as "filenames" in parsing.

Occurs in browser profiles.
Fix argument order and regexp.

File under: how did this ever work?
Add a new version of navier-stokes.