JIT

gh-142889: Restructure PyDictKeysObject memory layout for simpler access #5654

Job	Run time
aarch64-apple-darwin/clang (Release)	12m 36s
JIT with tail calling interpreter	4m 40s
aarch64-unknown-linux-gnu/gcc (Release)	7m 7s
Interpreter (Debug)	12m 7s
aarch64-pc-windows-msvc/msvc (Release)	19m 38s
JIT without optimizations (Debug)	3m 36s
aarch64-pc-windows-msvc/msvc (Debug)	25m 16s
Free-Threaded (Debug)	3m 48s
aarch64-unknown-linux-gnu/gcc (Debug)	8m 35s
i686-pc-windows-msvc/msvc (Release)	14m 36s
x86_64-pc-windows-msvc/msvc (Release)	14m 26s
i686-pc-windows-msvc/msvc (Debug)	28m 24s
x86_64-pc-windows-msvc/msvc (Debug)	28m 9s
x86_64-apple-darwin/clang (Debug)	40m 57s
x86_64-unknown-linux-gnu/gcc (Release)	8m 59s
x86_64-apple-darwin/clang (Release)	27m 56s
x86_64-unknown-linux-gnu/gcc (Debug)	13m 40s
aarch64-apple-darwin/clang (Debug)	14m 10s
	4h 48m 40s

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