Instead of allocating a small bundle for deferred deletion, store a
small triple of {Serial,VkHandle,HandleType}. The HandleType can be
used in a generic way to release the VkHandle, without needing to
store a pointer and use a virtual call.

BUG=angleproject:2200

Change-Id: I30925c2f50fd11dafb1b986ced7d279a7dde827b
Reviewed-on: https://chromium-review.googlesource.com/741163
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Frank Henigman <fjhenigman@chromium.org>