Add Reference.getReferent for reference intrinsic.

Reference intrinsic was incorrectly inlining PhantomReference.get().
We get around this by adding a layer of indirection. Reference.get()
now calls getReferent() which is intrinsified and inlined.

Bug: 17429865

(cherry picked from commit ee1ba6114921065ff4629cdaee207e2960dadd63)

Change-Id: I305686d76e0e03856a46b85955622939718c8d85
1 file changed