JIT

Don't make object immortal until it is fully initialized #668

Job	Run time
Interpreter (Debug)	9m 48s
i686-pc-windows-msvc/msvc (Release)	13m 13s
x86_64-pc-windows-msvc/msvc (Debug)	22m 35s
i686-pc-windows-msvc/msvc (Debug)	23m 15s
aarch64-pc-windows-msvc/msvc (Release)	19m 31s
aarch64-unknown-linux-gnu/gcc (Debug)	6m 59s
aarch64-apple-darwin/clang (Release)	9m 24s
aarch64-pc-windows-msvc/msvc (Debug)	22m 28s
x86_64-unknown-linux-gnu/gcc (Release)	6m 31s
x86_64-apple-darwin/clang (Release)	14m 6s
aarch64-apple-darwin/clang (Debug)	9m 49s
x86_64-pc-windows-msvc/msvc (Release)	13m 28s
aarch64-unknown-linux-gnu/gcc (Release)	5m 40s
x86_64-apple-darwin/clang (Debug)	15m 18s
x86_64-unknown-linux-gnu/gcc (Debug)	10m 51s
	3h 22m 56s

Provide feedback