JIT

GH-136895: Update JIT builds to use LLVM 20 #4188

Job	Run time
Interpreter (Debug)	9m 37s
JIT without optimizations (Debug)	12m 4s
Free-Threaded (Debug)	16m 17s
i686-pc-windows-msvc/msvc (Debug)	21m 5s
i686-pc-windows-msvc/msvc (Release)	11m 21s
x86_64-pc-windows-msvc/msvc (Release)	12m 3s
x86_64-apple-darwin/clang (Debug)	26m 8s
x86_64-apple-darwin/clang (Release)	18m 7s
aarch64-apple-darwin/clang (Debug)	14m 3s
aarch64-pc-windows-msvc/msvc (Debug)	21m 58s
x86_64-pc-windows-msvc/msvc (Debug)	21m 51s
aarch64-unknown-linux-gnu/gcc (Debug)	7m 7s
x86_64-unknown-linux-gnu/gcc (Release)	7m 6s
aarch64-apple-darwin/clang (Release)	9m 33s
aarch64-pc-windows-msvc/msvc (Release)	17m 45s
aarch64-unknown-linux-gnu/gcc (Release)	5m 50s
x86_64-unknown-linux-gnu/gcc (Debug)	12m 9s
	4h 4m 4s

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