gyp: isinstance -> type for another 1-5% save.
gyp: isinstance -> type for another 1-5% save.

isinstance is crazily slow. Save another 3 CPU seconds (<1 real second
with 8 cores) by using type() instead. This works well since we know
exactly what types we are using.

There are still some isinstance around, but only in cold paths where
performance doesn't matter.

BUG=362075

Review URL: https://codereview.chromium.org/232023006/
Patch from Daniel Bratell <bratell@opera.com>!

old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google