RFR: JDK-8210031: implementation for JVM Constants API

[Vicente Romero]

Please review the first iteration of the implementation for JEP-334 [1] 
JVM Constants API. The implementation can be found at [2]. JEP-334 
introduces an API to model nominal descriptions of key class-file and 
run-time artifacts, in particular constants that are loadable from the 
constant pool and has already been the subject of several discussions. 
The implementation of this JEP has been publicly accessible throw the 
amber repo at [3] in the jep-334 branch. Thanks to all members of the 
Amber project and specially to Brian for all the hard work on the design 
and the implementation of this API. Thanks for all the feedback we have 
received so far, most of it has been integrated in the current 
implementation.

Thanks,
Vicente

[1] http://openjdk.java.net/jeps/334
[2] http://cr.openjdk.java.net/~vromero/8210031/webrev.00/jdk.dev.patch
[3] http://hg.openjdk.java.net/amber/amber