On OSX, under ASAN the fuzzer is causing a null reference due to
.empty() being called on a null.
BUG=chromium:1237630
Change-Id: I73e627eadaa162af451f809c4abe8ec685d8b95c
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/61681
Auto-Submit: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>