During kernel state rewrite, handle functions passed as arguments.

src/irgen.jl

@@ -773,8 +773,27 @@ function add_kernel_state!(mod::LLVM.Module)
  @assert isempty(uses(val))
  unsafe_delete!(LLVM.parent(val), val)
  elseif val isa LLVM.CallBase
- # the function is being passed as an argument, which we'll just permit,
- # because we expect to have rewritten the call down the line separately.
+ # the function is being passed as an argument. to avoid having to
+ # rewrite the target function, instead case the rewritten function to
+ # the old stateless type.
+ # XXX: we won't have to do this with opaque pointers.
+ position!(builder, val)
+ target_ft = called_type(val)
+ new_args = map(zip(parameters(target_ft),
+ arguments(val))) do (param_typ, arg)
+ if value_type(arg) != param_typ
+ const_bitcast(arg, param_typ)
+ else
+ arg
+ end
+ end
+ new_val = call!(builder, called_type(val), called_value(val), new_args,
+ operand_bundles(val))
+ callconv!(new_val, callconv(val))
+
+ replace_uses!(val, new_val)
+ @assert isempty(uses(val))
+ unsafe_delete!(LLVM.parent(val), val)
  elseif val isa LLVM.StoreInst
  # the function is being stored, which again we'll permit like before.
  elseif val isa ConstantExpr