gh-150587: Guard specialized list-int subscript indices #3362

Job	Run time
x86_64-unknown-linux-gnu/gcc	9m 54s
aarch64-apple-darwin/clang	9m 2s
x86_64-apple-darwin/clang	17m 51s
x86_64-unknown-linux-gnu/gcc-free-threading	7m 56s
aarch64-unknown-linux-gnu/gcc	6m 57s
	51m 40s

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