Remove BoundArrayAccessors

BUG=tint:1212

Change-Id: I054bedb6f20ef18d70408087f774ef252403b49c
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/66100
Auto-Submit: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
diff --git a/src/transform/robustness.h b/src/transform/robustness.h
index a4478f1..fcade3a 100644
--- a/src/transform/robustness.h
+++ b/src/transform/robustness.h
@@ -52,8 +52,6 @@
   struct State;
 };
 
-using BoundArrayAccessors = Robustness;
-
 }  // namespace transform
 }  // namespace tint