f.Name["2"+r.Name.Go] = n
			}
			expr = getNewIdent(n.Mangle)
			r.Name = n
			break
		}
	case ctxExpr:
		switch r.Name.Kind {
		case "func":
			if builtinDefs[r.Name.C] != "" {
				error_(r.Pos(), "use of builtin '%s' not in function call", fixGo(r.Name.C))
			}

			// Function is being used in an expression, to e.g. pass around a C function pointer.