Implement `fixed_symbol` #84

Job	Run time
Publish	31s
Check clippy	22s
Check format	6s
release artifact for x86_64-pc-windows-gnu	1m 38s
Run tests	20s
release artifact for x86_64-pc-windows-msvc	1m 49s
release artifact for x86_64-apple-darwin	35s
release artifact for aarch64-apple-darwin	1m 10s
release artifact for x86_64-unknown-linux-musl	26s
release artifact for x86_64-unknown-linux-gnu	20s
	7m 17s

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