remove some intrinsics #2498

Job	Run time
build_system	24s
build (gcc-15.deb, --std-tests)	6m 0s
duplicates	3s
build (gcc-15.deb, --test-libcore)	14m 6s
build (gcc-15.deb, --extended-rand-tests)	8m 24s
build (gcc-15.deb, --extended-regex-example-tests)	6m 20s
build (gcc-15.deb, --extended-regex-tests)	11m 17s
build (gcc-15.deb, --test-successful-rustc --nb-parts 2 --current-part 0)	11m 27s
build (gcc-15.deb, --test-successful-rustc --nb-parts 2 --current-part 1)	11m 34s
build (gcc-15.deb, --projects)	11m 14s
build (gcc-15-without-int128.deb, --std-tests)	5m 52s
build (gcc-15-without-int128.deb, --test-libcore)	14m 50s
build (gcc-15-without-int128.deb, --extended-rand-tests)	8m 47s
build (gcc-15-without-int128.deb, --extended-regex-example-tests)	6m 33s
build (gcc-15-without-int128.deb, --extended-regex-tests)	11m 43s
build (gcc-15-without-int128.deb, --test-successful-rustc --nb-parts 2 --current-part 0)	12m 49s
build (gcc-15-without-int128.deb, --test-successful-rustc --nb-parts 2 --current-part 1)	11m 29s
build (gcc-15-without-int128.deb, --projects)	11m 28s
success	1s
	2h 44m 21s

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