Don't Consume into block for var()/env()
Fixes crash for invalid var(), e.g. var(--x ()).
Bug: 40941162
Change-Id: I1af790d4ce00659cff66076731110e055c98d0f3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5860522
Commit-Queue: Anders Hartvoll Ruud andruud@chromium.org
Reviewed-by: Steinar H Gunderson sesse@chromium.org
Cr-Commit-Position: refs/heads/main@{#1355439}