RFR: 8000404 java.lang.annotation.Native

[Jonathan Gibbons]

See http://cr.openjdk.java.net/~jjg/8000404/webrev/

A while back, we added a new annotation 
javax.tools.GenerateNativeHeader, to mark classes that contained 
constants of interest to native code, such that tools, like javac with 
the -h option, could generate know to generate native header files.   
Based on our experience in using the new annotation, we have decided to 
change to using a different annotation, with the same purpose:  
java.lang.annotation.Native, to be used to annotate the constants 
themselves.

This review is for step 1 of a 3 step process to replace 
javax.tools.GenerateNativeHeader with java.lang.annotation.Native.

This first step is to add the new annotation.

Separately, the goal is to replacing existing uses of 
@GenerateNativeHeader with @Native.   Then, we will remove 
javax.tools.GenerateNativeHeader.

-- Jon