Spec for Vec::extend_from_slice #6395

Job	Run time
smoke-test-and-release-macos-x86	8m 42s
smoke-test-and-release-linux	6m 21s
smoke-test-and-release-windows	8m 43s
fmt	1m 11s
test-and-release-macos	12m 12s
test-and-release-macos (record-history)	3m 39s
test-and-release-macos (no-std)	2m 29s
test-and-release-macos (no-alloc)	2m 22s
test-and-release-macos (singular)	2m 54s
test-and-release-macos (cvc5)	3m 33s
release	0s
	52m 6s

Provide feedback