Run jextract with libclang panama style

[Henry Jen]

Hi,

This webrev[1] add a test case that

1. Run jextract against libclang
2. Compile the module jdk.internal.clang implemented in libclang native API using panama stack instead of JNI
3. Run jextract itself on top of the libclang panama stack by patching jdk.internal.clang module
4. Compare result from step 1 and step 3 so that both should have same result

To run the test, run the verify.sh from within the test directory.

As for now, it’s sort of hacked together to demonstrate the process of using native library, in this case, libclang itself. By running jextract we get to test the binding is actually working. We will need to make it fit better with the testing framework.

Cheers,
Henry

[1] http://cr.openjdk.java.net/~henryjen/panama/clang-ffi/0/webrev/