lcm should throw when one arg is infinite and the other is finite

[LilithHafner]

julia> lcm(1//0, 3//2)
3//2 # Should throw

julia> lcm(1//0, 1//0)
1//0 # Correct

julia> lcm(0//1, 2//3)
0//1 # Correct

julia> lcm(1//0, -1//0)
1//0 # Correct

Originally posted by @LilithHafner as part of a comment from triage in #56423 (comment)

[LilithHafner]

Should we also make gcd(1//0, 1//1) throw?