Fix `--allowlist-item` so it doesn't ignore anon enums #2128

Job	Run time
rustfmt-clippy	29s
msrv	52s
check-cfg	23s
docs	29s
minimal	10s
quickchecking	23s
test-book	6s
test (ubuntu-latest, 9.0, 1, 0, 0, 0, 0)	1m 52s
test-expectations (ubuntu-latest)	54s
test (ubuntu-latest, 9.0, 1, 0, 0, 1, 0)	1m 50s
test-expectations (macos-12)	1m 29s
test (ubuntu-latest, 9.0, 1, 0, 1, 0, 0)	1m 56s
test (ubuntu-latest, 9.0, 1, 0, 1, 1, 0)	1m 55s
test (ubuntu-latest, 9.0, 1, 1, 0, 0, 0)	2m 24s
test (ubuntu-latest, 9.0, 1, 1, 0, 1, 0)	2m 15s
test (ubuntu-latest, 9.0, 1, 1, 1, 0, 0)	2m 17s
test (ubuntu-latest, 9.0, 1, 1, 1, 1, 0)	2m 10s
test (ubuntu-latest, 16.0, 1, 0, 0, 0, 0)	2m 35s
test (ubuntu-latest, 16.0, 1, 0, 0, 1, 0)	2m 39s
test (ubuntu-latest, 16.0, 1, 0, 1, 0, 0)	3m 42s
test (ubuntu-latest, 16.0, 1, 0, 1, 1, 0)	2m 32s
test (ubuntu-latest, 16.0, 1, 1, 0, 0, 0)	3m 3s
test (ubuntu-latest, 16.0, 1, 1, 0, 1, 0)	4m 6s
test (ubuntu-latest, 16.0, 1, 1, 1, 0, 0)	2m 59s
test (ubuntu-latest, 16.0, 1, 1, 1, 1, 0)	3m 10s
test (ubuntu-latest, 16.0, 0, 0, 1)	2m 5s
test (macos-12, 9.0, 0, 0, 0)	1m 27s
success	3s
	50m 15s

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