Review request for JDK-8062141: Various performance issues parsing JSON

[Hannes Wallnoefer]

Please review JDK-8062141: Various performance issues parsing JSON:
http://cr.openjdk.java.net/~hannesw/8062141/

Thew new JSON parser is about 2-3 x faster than our old one, roughly on 
par with the ones in Rhino or V8.

Hannes