Consistently use a separate Lithium instruction for flooring division.

src/x64/lithium-x64.h

Index: src/x64/lithium-x64.h
diff --git a/src/x64/lithium-x64.h b/src/x64/lithium-x64.h
index 9d9ac1ea17c496d71bfc79f11ef87cef48686198..1c8bb0d381d23f749849636136134ef03500c6aa 100644
--- a/src/x64/lithium-x64.h
+++ b/src/x64/lithium-x64.h
@@ -97,6 +97,7 @@ class LCodeGen;
   V(Dummy)                                      \
   V(FlooringDivByConstI)                        \
   V(FlooringDivByPowerOf2I)                     \
+  V(FlooringDivI)                               \
   V(ForInCacheArray)                            \
   V(ForInPrepareMap)                            \
   V(FunctionLiteral)                            \
@@ -732,14 +733,14 @@ class LDivByConstI V8_FINAL : public LTemplateInstruction<1, 1, 2> {
 
 class LDivI V8_FINAL : public LTemplateInstruction<1, 2, 1> {
  public:
-  LDivI(LOperand* left, LOperand* right, LOperand* temp) {
-    inputs_[0] = left;
-    inputs_[1] = right;
+  LDivI(LOperand* dividend, LOperand* divisor, LOperand* temp) {
+    inputs_[0] = dividend;
+    inputs_[1] = divisor;
     temps_[0] = temp;
   }
 
-  LOperand* left() { return inputs_[0]; }
-  LOperand* right() { return inputs_[1]; }
+  LOperand* dividend() { return inputs_[0]; }
+  LOperand* divisor() { return inputs_[1]; }
   LOperand* temp() { return temps_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(DivI, "div-i")
@@ -794,6 +795,23 @@ class LFlooringDivByConstI V8_FINAL : public LTemplateInstruction<1, 1, 3> {
 };
 
 
+class LFlooringDivI V8_FINAL : public LTemplateInstruction<1, 2, 1> {
+ public:
+  LFlooringDivI(LOperand* dividend, LOperand* divisor, LOperand* temp) {
+    inputs_[0] = dividend;
+    inputs_[1] = divisor;
+    temps_[0] = temp;
+  }
+
+  LOperand* dividend() { return inputs_[0]; }
+  LOperand* divisor() { return inputs_[1]; }
+  LOperand* temp() { return temps_[0]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(FlooringDivI, "flooring-div-i")
+  DECLARE_HYDROGEN_ACCESSOR(MathFloorOfDiv)
+};
+
+
 class LMulI V8_FINAL : public LTemplateInstruction<1, 2, 0> {
  public:
   LMulI(LOperand* left, LOperand* right) {
@@ -2681,12 +2699,13 @@ class LChunkBuilder V8_FINAL : public LChunkBuilderBase {
   LInstruction* DoMathClz32(HUnaryMathOperation* instr);
   LInstruction* DoDivByPowerOf2I(HDiv* instr);
   LInstruction* DoDivByConstI(HDiv* instr);
-  LInstruction* DoDivI(HBinaryOperation* instr);
+  LInstruction* DoDivI(HDiv* instr);
   LInstruction* DoModByPowerOf2I(HMod* instr);
   LInstruction* DoModByConstI(HMod* instr);
   LInstruction* DoModI(HMod* instr);
   LInstruction* DoFlooringDivByPowerOf2I(HMathFloorOfDiv* instr);
   LInstruction* DoFlooringDivByConstI(HMathFloorOfDiv* instr);
+  LInstruction* DoFlooringDivI(HMathFloorOfDiv* instr);
 
  private:
   enum Status {