First class functions, function types, conversion functions #642

Job	Run time
Documentation checks	4m 25s
WASM version	1m 28s
Ensure 'cargo fmt' has been run	15s
Extract crate metadata	5s
Minimum supported rust version	1m 36s
aarch64-unknown-linux-gnu (ubuntu-20.04)	3m 32s
arm-unknown-linux-gnueabihf (ubuntu-20.04)	3m 29s
arm-unknown-linux-musleabihf (ubuntu-20.04)	3m 9s
i686-pc-windows-msvc (windows-2019)	5m 15s
i686-unknown-linux-gnu (ubuntu-20.04)	2m 59s
i686-unknown-linux-musl (ubuntu-20.04)	3m 3s
x86_64-apple-darwin (macos-12)	3m 37s
x86_64-pc-windows-msvc (windows-2019)	4m 31s
x86_64-unknown-linux-gnu (ubuntu-20.04)	2m 51s
x86_64-unknown-linux-musl (ubuntu-20.04)	3m 1s
	43m 16s

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