This CL adds infrastructure for tracking whether resources need to be
reset when looping back to the beginning of the frame sequence.

A new function is generated on the last frame: ResetContext*Replay().
It will contain calls to gen, delete, and restore contents of
resources. This CL only supports Buffer resets.

Bug: b/152512564
Bug: angleproject:3662
Bug: angleproject:4599
Change-Id: I46672dd70dcb997967e3cc0897308144f2582e21
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2168121
Commit-Queue: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>