Revert "bring fieldtype typefunc closer to the actual fieldtype builtin"

This reverts commit e3c5c11bc3f1833554166f160c842f167d0f77fc.

Conflicts:
	test/core.jl

Since this prevents Pkg operation, which is pretty common, it's best to
revert it for now.
Merge branch 'master' of github.com:JuliaLang/julia