JIT

gh-140889: Bump tailcall and JIT CI to llvm 20 #4268

Job	Run time
Interpreter (Debug)	10m 10s
JIT with tail calling interpreter (20)	3m 23s
JIT without optimizations (Debug) (20)	10m 50s
Free-Threaded (Debug) (20)	16m 29s
i686-pc-windows-msvc/msvc (Debug)	21m 13s
i686-pc-windows-msvc/msvc (Release)	11m 36s
x86_64-pc-windows-msvc/msvc (Debug)	20m 21s
aarch64-pc-windows-msvc/msvc (Release)	15m 41s
aarch64-pc-windows-msvc/msvc (Debug)	20m 50s
aarch64-apple-darwin/clang (Debug)	10m 44s
x86_64-apple-darwin/clang (Release)	29m 32s
x86_64-unknown-linux-gnu/gcc (Release)	7m 15s
x86_64-pc-windows-msvc/msvc (Release)	11m 53s
x86_64-apple-darwin/clang (Debug)	44m 4s
x86_64-unknown-linux-gnu/gcc (Debug)	12m 52s
aarch64-unknown-linux-gnu/gcc (Debug)	7m 10s
aarch64-apple-darwin/clang (Release)	9m 34s
aarch64-unknown-linux-gnu/gcc (Release)	5m 24s
	4h 29m 1s

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