Function to generate a call from the def Dict

[oxinabox]

Given the dict returned by splitdef
it would be useful to have a function the generate a Expr(:call,... to the function that is defined.

e.g.

julia> k = splitdef(:(f(x::Int) = 2x))
Dict{Symbol,Any} with 4 entries:
  :args => Any[:(x::Int)]
  :body => quote…
  :name => :f
  :head => :(=)

julia> call_expr(k) == :(f(x))

This is basically a much simpler version of combinedef

[omus]

That's reasonable. I'd have to think about naming a little more here

[oxinabox]

In a meaningful way #17 addresses this.
Not entirely, though.