RFR: JDK-8180744: Update ct.sym for JDK 10

[Jan Lahoda]

Hi,

The patch here adds a support for --release 9 to OpenJDK. This includes 
adding a snapshot of the JDK 9 APIs.

Notes:
-several changes to the historical data in make/data/symbols:
--java.management.rmi-8.sym.txt contains a few classes that were 
originally in java.management-8.sym.txt (this change is adjusting the 
structure to adhere more to the final JDK 9 module layout)
--java.annotations.common-* renamed to java.xml.ws.annotation-* to 
adhere to the final layout
--diffing of classes across releases has been improved to avoid some 
unnecessary class header notices in the historical data
--empty files are now not written for the historical data
-the (JDK)PlatformProvider.PlatformDescription(Impl) now returns a file 
manager, instead of a list of paths. This makes the contract cleaner, 
and allow to handle the ".sig" extension mostly in the file manager 
instead of ClassFinder. (Due to this change, JDK-8139607: '-release 
option forces StandardJavaFileManager' is also resolved by this patch, 
although it is not the primary goal of this patch.)

Bug: https://bugs.openjdk.java.net/browse/JDK-8180744
Webrev: http://cr.openjdk.java.net/~jlahoda/8180744/webrev.00/

I'll send to build-dev as well after the javac changes will look OK.

Any feedback is welcome.

Thanks,
     Jan