The ValidateStructure method only required the current pipeline stage.
Pass that in directly instead of depending on current_function_.
Bug: tint:1313
Change-Id: I13a429aa9d77c8c43fb82d2aa02b25e05b0e3a6c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/87143
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>