Annotate anonymous mmap #222

Job	Run time
cargo test	40s
make (check, --enable-yjit, --yjit)	9m 41s
make (check, --enable-yjit=dev, --yjit-call-threshold=1 --yjit-verify-ctx --yjit-code-gc, -T --yj...	24m 42s
YJIT macOS Arm64 result	1s
	35m 4s

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