Add monomorphic CompareNilICs and Crankshaft support

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index a2dbe7de1df27f45fa1650555a05d3f06b98073f..23619c8a8ad0b78f32eab845ebaea773d0f6ae29 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -304,10 +304,13 @@ class HGraph: public ZoneObject {
   HConstant* GetConstantUndefined() const { return undefined_constant_.get(); }
   HConstant* GetConstant0();
   HConstant* GetConstant1();
+  HConstant* GetConstantSmi0();
+  HConstant* GetConstantSmi1();
   HConstant* GetConstantMinus1();
   HConstant* GetConstantTrue();
   HConstant* GetConstantFalse();
   HConstant* GetConstantHole();
+  HConstant* GetConstantNull();
   HConstant* GetInvalidContext();
 
   HBasicBlock* CreateBasicBlock();
@@ -395,6 +398,8 @@ class HGraph: public ZoneObject {
  private:
   HConstant* GetConstantInt32(SetOncePointer<HConstant>* pointer,
                               int32_t integer_value);
+  HConstant* GetConstantSmi(SetOncePointer<HConstant>* pointer,
+                            int32_t integer_value);
 
   void MarkAsDeoptimizingRecursively(HBasicBlock* block);
   void NullifyUnreachableInstructions();
@@ -424,10 +429,13 @@ class HGraph: public ZoneObject {
   SetOncePointer<HConstant> undefined_constant_;
   SetOncePointer<HConstant> constant_0_;
   SetOncePointer<HConstant> constant_1_;
+  SetOncePointer<HConstant> constant_smi_0_;
+  SetOncePointer<HConstant> constant_smi_1_;
   SetOncePointer<HConstant> constant_minus1_;
   SetOncePointer<HConstant> constant_true_;
   SetOncePointer<HConstant> constant_false_;
   SetOncePointer<HConstant> constant_the_hole_;
+  SetOncePointer<HConstant> constant_null_;
   SetOncePointer<HConstant> constant_invalid_context_;
   SetOncePointer<HArgumentsObject> arguments_object_;
 
@@ -890,7 +898,6 @@ class HIfContinuation {
                HBasicBlock* false_branch,
                int position) {
     ASSERT(!continuation_captured_);
-    ASSERT(true_branch != NULL || false_branch != NULL);
     true_branch_ = true_branch;
     false_branch_ = false_branch;
     position_ = position;
@@ -1023,6 +1030,7 @@ class HGraphBuilder {
     HValue* CheckNotUndefined(HValue* value);
     HValue* CheckIntegerCompare(HValue* left, HValue* right, Token::Value op);
     HValue* CheckIntegerEq(HValue* left, HValue* right);
+
     void End();
 
    private:
@@ -1129,6 +1137,7 @@ class HGraphBuilder {
     void End();
 
     void Deopt();
+    void Return(HValue* value);
 
    private:
     void AddCompare(HControlInstruction* compare);
@@ -1246,6 +1255,14 @@ class HGraphBuilder {
                                  ElementsKind kind,
                                  int length);
 
+  void BuildCompareNil(
+      HValue* value,
+      EqualityKind kind,
+      CompareNilICStub::Types types,
+      Handle<Map> map,
+      int position,
+      HIfContinuation* continuation);
+
  private:
   HGraphBuilder();
   CompilationInfo* info_;