These can be used in all sorts of places which are not tracked by sem::Function::TransitivelyReferencedGlobals().
As they're not emitted as variables by any backend, just preserve them.
Fixed: tint:1598
Change-Id: I2696486cb2ffe8408bd5dd3090d7d600ca1d170f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/101481
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Auto-Submit: Ben Clayton <bclayton@google.com>
Ben Clayton