Fix undefined symbols error with lto #1732

Job	Run time
build (--test-libcore)	2m 24s
build (--test-successful-rustc --nb-parts 2 --current-part 1)	2m 43s
build (--mini-tests)	2m 41s
build (--std-tests)	49s
build (--test-successful-rustc --nb-parts 2 --current-part 0)	1m 16s
success_gcc12	3s
	9m 56s

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