JIT

further test refinements. #1

Job	Run time
i686-pc-windows-msvc/msvc (Debug)	15m 18s
i686-pc-windows-msvc/msvc (Release)	19m 51s
x86_64-pc-windows-msvc/msvc (Debug)	15m 30s
x86_64-pc-windows-msvc/msvc (Release)	19m 50s
x86_64-apple-darwin/clang (Debug)	15m 54s
x86_64-apple-darwin/clang (Release)	15m 57s
aarch64-apple-darwin/clang (Debug)	9m 17s
aarch64-apple-darwin/clang (Release)	11m 53s
x86_64-unknown-linux-gnu/gcc (Debug)	8m 35s
x86_64-unknown-linux-gnu/gcc (Release)	16m 21s
x86_64-unknown-linux-gnu/clang (Debug)	6m 50s
x86_64-unknown-linux-gnu/clang (Release)	13m 20s
aarch64-unknown-linux-gnu/gcc (Debug)	56m 2s
aarch64-unknown-linux-gnu/gcc (Release)	45m 28s
aarch64-unknown-linux-gnu/clang (Debug)	50m 19s
aarch64-unknown-linux-gnu/clang (Release)	29m 34s
	5h 49m 59s

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