JIT

gh-134273: Allow setting JIT compiler flags with `CFLAGS_JIT` #3488

Job	Run time
Interpreter (Debug)	10m 7s
i686-pc-windows-msvc/msvc (Debug)	2m 37s
i686-pc-windows-msvc/msvc (Release)	2m 29s
x86_64-pc-windows-msvc/msvc (Debug)	2m 5s
x86_64-pc-windows-msvc/msvc (Release)	1m 39s
aarch64-pc-windows-msvc/msvc (Debug)	4m 13s
aarch64-pc-windows-msvc/msvc (Release)	4m 13s
x86_64-apple-darwin/clang (Debug)	6m 44s
x86_64-apple-darwin/clang (Release)	6m 38s
aarch64-apple-darwin/clang (Debug)	2m 55s
aarch64-apple-darwin/clang (Release)	2m 42s
x86_64-unknown-linux-gnu/gcc (Debug)	10m 58s
x86_64-unknown-linux-gnu/gcc (Release)	6m 30s
aarch64-unknown-linux-gnu/gcc (Debug)	7m 58s
aarch64-unknown-linux-gnu/gcc (Release)	5m 42s
	1h 17m 30s

Provide feedback