Review request for JDK-8053905: Eager code generation fails for earley boyer with split threshold set to 1000

[Hannes Wallnoefer]

Please review JDK-8053905: Eager code generation fails for earley boyer 
with split threshold set to 1000:

http://cr.openjdk.java.net/~hannesw/8053905/

This involves a bit of refactoring around StoredScript which makes the 
handling of persisted scripts a bit cleaner and allows us to restore the 
old sanity check we had in place when setting code in 
RecompilableScriptFunctionData.

Thanks,
Hannes