PR18455: use an initial type resolution pass

PR18455: use an initial type resolution pass

elaborate.cxx: for the const_folder visitor attempt to resolve some
times before the const_foler visitor is called. this is to try to
propogate an expression's type that is implied by what expression it's
in, up to the vardecl, to avoid unresolved type errors in cases like:
{println(i*0)}