Add ctx.ModuleDir and top level module dirs of input sources to JDK9

--patch-module lookup.

javac --patch-module accepts a list of directories and/or jars for JDK9
module patching (see bug for more details). In Bazel-Ninja execution,
Bazel executes the javac action in its own execution root working
directory, unlike Ninja, which works in the Android top level directory.
The Bazel execution root is formed of a symlink forest of top level
directories. This symlink forest is a problem for javac because it
doesn't traverse into symlinks.

To support Bazel executing these javac actions, we explicitly encode the
module directory, and the top level directory of any other source file
inputs into the --patch-module javac flag.

For example, the "core-all" libcore module compiles into `java.base`,
and depends on filegroups outside of `libcore` (`tools`). This CL adds
`tools` to the --patch-module lookup dir, on top of `libcore`.

See java_test.go for more details.

Bug: 150878007
Fixes: 150878007
Test: m
Test: bazel build droid (aosp_flame)
Change-Id: Id95b0a9a675fc75678f7b5e600344b4403f0c518