Add missing Fanotify APIs from the libc crate into Nix. #1628

Job	Run time
linux_native_builds (x86_64-unknown-linux-gnu)	41s
minver	14s
macos	3m 4s
macos-aarch64	1m 42s
linux_native_builds (x86_64-unknown-linux-musl)	43s
rust_stable	33s
rustfmt	11s
solaris (x86_64-pc-solaris)	3m 1s
tier3 (x86_64-unknown-dragonfly)	1m 4s
tier3 (x86_64-unknown-openbsd)	1m 2s
tier3 (x86_64-unknown-haiku)	59s
tier3 (armv7-unknown-linux-uclibceabihf)	45s
cross_compiling	0s
cross	0s
redox	0s
	13m 59s

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