merge_pr_51088

[functions] Add more invalid cases to WPT at-function-parsing.html

Since this test was added, the prelude grammar has grown quite a bit;
add some new cases to verify that we actually respect
.

Fixed: 389951206
Bug: 325504770
Change-Id: Iaf7751c537aa580582a04f19383df3fc06215992
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6322427
Reviewed-by: Steinar H Gunderson sesse@chromium.org
Commit-Queue: Anders Hartvoll Ruud andruud@chromium.org
Cr-Commit-Position: refs/heads/main@{#1427654}