JIT

gh-142889: Restructure PyDictKeysObject memory layout for simpler access #5482

Job	Run time
JIT without optimizations (Debug)	3m 37s
Interpreter (Debug)	27m 44s
Free-Threaded (Debug)	3m 51s
aarch64-apple-darwin/clang (Release)	11m 6s
x86_64-apple-darwin/clang (Debug)	50m 27s
x86_64-unknown-linux-gnu/gcc (Release)	8m 56s
JIT with tail calling interpreter	4m 34s
aarch64-apple-darwin/clang (Debug)	14m 9s
aarch64-pc-windows-msvc/msvc (Debug)	25m 5s
aarch64-unknown-linux-gnu/gcc (Debug)	9m 11s
aarch64-pc-windows-msvc/msvc (Release)	18m 21s
x86_64-pc-windows-msvc/msvc (Debug)	26m 59s
aarch64-unknown-linux-gnu/gcc (Release)	6m 42s
x86_64-pc-windows-msvc/msvc (Release)	15m 17s
i686-pc-windows-msvc/msvc (Release)	15m 24s
x86_64-apple-darwin/clang (Release)	30m 45s
i686-pc-windows-msvc/msvc (Debug)	27m 52s
x86_64-unknown-linux-gnu/gcc (Debug)	13m 45s
	5h 13m 45s

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