suggestion and offer: langtools in build

[Jonathan Gibbons]

OK, I realize you guys are really busy right now, so you may want to 
save this for a bit later ...

It bugs me that the new build creates lots of jar files for langtools, 
that only differ in the main program.

   updating 1739 files
   updating 1739 files
   updating 1739 files
Modifying langtools/dist/lib/classes.jar
   updating 1749 files

How about changing it so that we create a single jar file (classes.jar) 
that contains a "build-time only" main program which is a wrapper for 
all the necessary tools, such that the first arg identifies the tool.

Thus the downstream use is simply to replace

     BOOTJAVAHOME/bin/java -jar javac.jar args

with

     BOOTJAVAHOME/bin/java -jar classes.jar javac args

If you (build-infra guys) are interested, I'll provide the main program 
to go in the langtools repo. This would be for the build only -- there 
is no suggestion to put it in any external product.

-- Jon