tree ff711b13c400a23693160f4bb3588e369ef9f617
parent 71a0a7c91e7511ccff85e365e5787626f21bc6eb
author dan sinclair <dsinclair@chromium.org> 1750099827 -0700
committer Dawn LUCI CQ <dawn-scoped@luci-project-accounts.iam.gserviceaccount.com> 1750099827 -0700

Add simple dead code eliminator transform.

This CL adds a new transform, used by the SPIR-V Reader lower pass, to
do a simple dead code elimination pass over the module. To start this
pass will remove:

* Unused functions.
* Unused module scoped `__in`, `__out` and `private` vars.

The SPIR-V IR reader pass then uses this to remove any unused
Input/Output variables from the program.

Bug: 42250952
Change-Id: I9022248702cde50c020dc7724a609333172604b3
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/246694
Reviewed-by: James Price <jrprice@google.com>
Commit-Queue: dan sinclair <dsinclair@chromium.org>