Remove unrelated confusing comment

Author: oxinabox

src/codegen/forward_demand.jl

@@ -105,7 +105,6 @@ function forward_diff_uncached!(ir::IRCode, interp::AbstractInterpreter, irsv::I
             Δbacking = insert_node!(ir, ssa, NewInstruction(Expr(:splatnew, widenconst(tup_typ), Δbacking), tup_typ_typ.val))
         end
         tangentT = Core.Compiler.apply_type_tfunc(Const(ChainRulesCore.Tangent), newT, tup_typ_typ).val
-        # TODO do we need to make sure this inserts right 
         Δtangent = insert_node!(ir, ssa, NewInstruction(Expr(:new, tangentT, Δbacking), tangentT))
         return Δtangent
     else # general frule handling