utop mishandles floating-point unary negation

[MarkJosephs]

utop # -. 1;;

• : int = -1

In contrast, ocaml underlines 1 and reports

Error: This expression has type int but an expression was expected of type float

[whitequark]

This is the fault of camlp4. Bare utop (without camlp4) exhibits same behavior as ocaml.