[wpt] Fix null-handling in equals JS String Builtins
Equals specifically allows null inputs. Update the JS API
tests and the polyfill to match, and remove expectations files
now that the basic tests pass.
The test changes are mirrored in an upstream PR:
WebAssembly/js-string-builtins#43
Bug: 42204114
Change-Id: I170f7e26e80033844a1d3e95fbe998d5f64f4a47
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5836264
Reviewed-by: Rezvan Mahdavi Hezaveh rezvan@chromium.org
Commit-Queue: Adam Klein adamk@chromium.org
Cr-Commit-Position: refs/heads/main@{#1350946}