[turbofan] Math.random never produces -0.

src/compiler/typer.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/typer.h"
 
 #include <iomanip>
 
 #include "src/base/flags.h"
 #include "src/bootstrapper.h"
@@ skipping 1277 matching lines @@
 Type* Typer::Visitor::JSCallFunctionTyper(Type* fun, Typer* t) {
   if (fun->IsFunction()) {
     return fun->AsFunction()->Result();
   }
   if (fun->IsConstant() && fun->AsConstant()->Value()->IsJSFunction()) {
     Handle<JSFunction> function =
         Handle<JSFunction>::cast(fun->AsConstant()->Value());
     if (function->shared()->HasBuiltinFunctionId()) {
       switch (function->shared()->builtin_function_id()) {
         case kMathRandom:
-          return Type::OrderedNumber();
+          return Type::PlainNumber();
         case kMathFloor:
         case kMathCeil:
         case kMathRound:
         case kMathTrunc:
           return t->cache_.kIntegerOrMinusZeroOrNaN;
         // Unary math functions.
         case kMathAbs:
         case kMathExp:
         case kMathExpm1:
           return Type::Union(Type::PlainNumber(), Type::NaN(), t->zone());
@@ skipping 410 matching lines @@
 Type* Typer::Visitor::TypeConstant(Handle<Object> value) {
   if (Type::IsInteger(*value)) {
     return Type::Range(value->Number(), value->Number(), zone());
   }
   return Type::Constant(value, zone());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8