These changes were made by manually running `rustfmt` on all of the test files,
and then manually undoing all cases where the original formatting appeared to
have been deliberate.
`rustfmt +nightly --config-path=/dev/null --edition=2021 tests/run-coverage*/**/*.rs`
When one of these tests fails, any compiler warnings will be printed to the
console, which makes it harder to track down the actual reason for failure.
(The outstanding warnings were found by temporarily adding `-Dwarnings` to the
compiler arguments for `RunCoverage` in `src/tools/compiletest/src/runtest.rs`.)
Andy Caldwell