Extending a constructor is possible without explicit `import` or module prefix

[KristofferC]

Not sure if this is intended:

julia> UUID
ERROR: UndefVarError: UUID not defined

julia> using Random: UUID

julia> UUID(x::String) = UUID(rand(UInt128)) # OK?
UUID

julia> UUID("foo")
8c68d00a-33d1-777d-c4a1-0a41759d1581

julia> using Base: getindex

julia> struct Foo end

julia> getindex(::Foo) = print("Hello")
ERROR: error in method definition: function Base.getindex must be explicitly imported to be extended

[KristofferC]

Ref #37783 which has the extra bonus of having a const => = Pair making it even harder to spot.

[nickrobinson251]

Can this not be in a v1.x release, if we consider it to be a bug? (And subject to PkgEval telling us it's not relied on too much)