tidy: rustdoc.d.js is allowed to have trailing whitespace

Summary

This file is not checked for trailing whitespace by tidy, and eslint is set to ignore large portions of it.

Command used

# after intentionally adding trailing whitespace to `rustdoc.d.js` (make sure your editor isn't removing the whitespace automatically)
./x test tidy

Expected behaviour

Either tidy or eslint complains about the trailing whitespace.

Actual behaviour

No warning

Bootstrap configuration (bootstrap.toml)

profile = "tools"  # Includes one of the default files in src/bootstrap/defaults
change-id = 138986

rust.download-rustc = false
rust.deny-warnings = false
build.docs-minification = false

Operating system

Arch Linux

HEAD

8ce228758651aa58c4d34e3bd65bf70a251da27e

Additional context

Building bootstrap
    Finished `dev` profile [unoptimized] target(s) in 0.03s
Building stage0 tool tidy (x86_64-unknown-linux-gnu)
    Finished `release` profile [optimized] target(s) in 0.07s
fmt check
fmt: skipped untracked file 0001-scrape-examples.js-give-each-function-a-signature.patch
fmt: skipped untracked file 0002-rustdoc-js-add-ScrapedLoc-type.patch
fmt: skipped untracked file 0003-rustdoc-js-add-rustdoc.ScrapedLoc-type.patch
fmt: skipped untracked file perf.data
fmt: checked modified file library/core/src/ptr/const_ptr.rs
fmt: checked modified file library/core/src/ptr/mut_ptr.rs
tidy check
Running eslint on rustdoc JS files
x.py completions check
Build completed successfully in 0:00:06

Inspect the tidy check invoked by ./x test tidy and the eslint configuration affecting rustdoc.d.js. Add or adjust the relevant check so intentionally added trailing whitespace produces a warning, then rerun ./x test tidy to confirm the issue is detected.