MethodHandles: Implement the first set of transforms.

Implements support for :

- MethodHandles.dropArguments.
- MethodHandles.catchException.
- MethodHandles.guardWithTest.

Even though this doesn't involve runtime changes, note that tests are
in art/ because the runtime still needs a flag to enable method handles.

This change also fixes a bug in MethodHandles.throwException; the method
must throw the argument instance passed to it.

Test: make test-art-host
Bug: 30550796

Change-Id: I0307ce098185119c0a7a6838aa53df463184e755