`precompile´ should maybe error when given non type inputs?

[KristofferC]

julia> precompile(Tuple{typeof(Base.isequal), Int, Int})
true

julia> precompile(Tuple{typeof(Base.isequal), 1, 2})
false

Instead of returning false, maybe this should error since AFAIU these input are pretty much nonsense.

[NHDaly]

Is there still a decision needed here? Or can we agree on this as being desirable, and mark it as good-first-issue?

[NHDaly]

CC: @vtjnash I think you might have decision-making ability here?

[vtjnash]

I don't think precompile having errors is a good or necessary idea. That usually has resulted in packages becoming un-installable and getting kicked out of PkgEval CI for no good reason.

[oscardssmith]

I think this should at least be a warnign, but tagging this for triage.