Fix bugs in simplified lowering relating to int32/uint32 signs.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index 0fa2b95ebd3460350def99acdd14b2341d7b1b00..99f4f8924175597a81545d0ea209d33adb3ae435 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -1033,8 +1033,7 @@ Type* Typer::Visitor::JSModulusTyper(Type* lhs, Type* rhs, Typer* t) {
   lhs = Rangify(lhs, t);
   rhs = Rangify(rhs, t);
   if (lhs->IsRange() && rhs->IsRange()) {
-    // TODO(titzer): fix me.
-    //    return JSModulusRanger(lhs->AsRange(), rhs->AsRange(), t);
+    return JSModulusRanger(lhs->AsRange(), rhs->AsRange(), t);
   }
   return Type::OrderedNumber();
 }