Fixed range analysis for HMathFloorOfDiv.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index d6cd1e6a20fbc5111ad2ba661ecda7c210f8c4d2..5c0a1e9594ef28c850cfd2ac34e3d95009200557 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -3762,6 +3762,9 @@ class HBinaryOperation : public HTemplateInstruction<3> {
 
   DECLARE_ABSTRACT_INSTRUCTION(BinaryOperation)
 
+ protected:
+  Range* InferRangeForDiv(Zone* zone);
+
  private:
   bool IgnoreObservedOutputRepresentation(Representation current_rep);
 
@@ -4102,12 +4105,12 @@ class HMathFloorOfDiv V8_FINAL : public HBinaryOperation {
     set_representation(Representation::Integer32());
     SetFlag(kUseGVN);
     SetFlag(kCanOverflow);
-    if (!right->IsConstant()) {
-      SetFlag(kCanBeDivByZero);
-    }
+    SetFlag(kCanBeDivByZero);
     SetFlag(kAllowUndefinedAsNaN);
   }
 
+  virtual Range* InferRange(Zone* zone) V8_OVERRIDE;
+
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };