Ant is no longer maintained, and as a result there's no module-
based version of its jar. We must move this out to a separate
library that can be used at build time, such as during JRuby's own
uses of the Rake ant targets.

We only have this dependency due to the @generated annotation we
add to some generated sources, but neither we nor anyone else ever
consumes that annotation.

Default scope for copy-dependencies is "test", which copies all
runtime, provided, and test dependencies. We only want runtime in
lib/modules.

This patch makes it possible to boot JRuby fully modularized. A
few notes:

* The org.jruby.base module is now open, because I was too lazy
  to individually open all of the Ruby kernel paths and there is
  no way to open them recursively from module-info.
* Ruby "kernel" sources have been moved into org.jruby.kernel to
  aid in accessing them in a module-friendly way. This does,
  unfortunately, result in paths like
  org/jruby/kernel/kernel/kernel.rb. An alternative name may be in
  order.

Using lookup() appears to return a Lookup object that is stricter
about access restrictions from a parent module to a child
classloader with no module. In this case, the variables in the
reified object classes are to be wired up in accessors. Using the
lookup() version results in an error:

java.lang.IllegalAccessException: symbolic reference class is not accessible: class org.jruby.gen.RubyObject5, from class org.jruby.specialized.RubyObjectSpecializer (module org.jruby.base)

Without this you cannot incrementally build. For some reason clean
build still works.

* Drop another Ant reference in favor of Java 11 Files.readString.
* Remove unnecessary and absent java.xml.ws.annotation module.

This was added as a dependency prior to modularization, but the
modularization work was rebased on top of a more recent version.

If we get a NCDFE attempting to reflect against the java.sql
DriverManager, it's pretty unlikely we were able to load anything
into it either. If we didn't load it, we don't care if we can't
clear it.

This allows us to move java.sql back to requires static since it is
only needed when used.