Fix show on InplaceableThunks

[oxinabox]

@nickrobinson251 pointed out:

(not this PR, afaiu): InplaceableThunk prints kinda funny (split over two lines)

julia> ithunk
InplaceableThunk(Thunk(var"#15#17"())
, var"#16#18"())

Because repr(::Thunk) hcalls show(::Thunk) which calls println
so we need to strip it out before using it in the show for InplaceThunk.

idk if this is the right fix, or if the problem is that show(::Thunk) should just use print not println ?

[nickrobinson251]

should just use print not println ?

Yeah using print sounds right to me