[roll] Roll fuchsia [starnix][binder] Implement hwbinder buffer objects

BINDER_TYPE_PTR buffer objects represent pointers to objects in the
sender's address space. These objects can be pointed to by other
buffers, and encode this information as their "parent buffer".

The binder driver copies all the buffers into the receiver's address
space, then corrects all the pointers within the buffers to the sender's
address space.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/684324
Original-Revision: 168ed43f998a3927d2e27f439025bdd765912dd6
GitOrigin-RevId: efc59690098c437eb9546b186f531d48fd7e8211
Change-Id: Ibf24e928b7f074f10458bb87e20012da77291905
diff --git a/stem b/stem
index c3e1a6d..07f9ad2 100644
--- a/stem
+++ b/stem
@@ -10,7 +10,7 @@
              githooks=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="14cb27e00ae7b44cf3a0bd375728052ed78d7e39"/>
+             revision="168ed43f998a3927d2e27f439025bdd765912dd6"/>
   </projects>
   <hooks>
     <hook name="install-environment"