First pass at emitIAS for branches and binding labels

src/assembler_ia32.h

Index: src/assembler_ia32.h
diff --git a/src/assembler_ia32.h b/src/assembler_ia32.h
index bb3f0ab63b2e439eecf7411720f0bc9fa9c44deb..452e3e22275349045eedb1551146d3a12a042b65 100644
--- a/src/assembler_ia32.h
+++ b/src/assembler_ia32.h
@@ -284,7 +284,9 @@ public:
 #endif // !NDEBUG
   }
 
-  ~Label() {
+  ~Label() {}
+
+  void FinalCheck() const {
     // Assert if label is being destroyed with unresolved branches pending.
     assert(!IsLinked());
     assert(!HasNear());
@@ -363,11 +365,14 @@ public:
     assert(!use_far_branches);
     (void)use_far_branches;
   }
-  ~AssemblerX86() {}
+  ~AssemblerX86() override;
 
   static const bool kNearJump = true;
   static const bool kFarJump = false;
 
+  Label *GetOrCreateCfgNodeLabel(SizeT NodeNumber);
+  void BindCfgNodeLabel(SizeT NodeNumber) override;
+
   // Operations to emit GPR instructions (and dispatch on operand type).
   typedef void (AssemblerX86::*TypedEmitGPR)(Type, GPRRegister);
   typedef void (AssemblerX86::*TypedEmitAddr)(Type, const Address &);
@@ -848,6 +853,9 @@ private:
   void EmitGenericShift(int rm, Type Ty, const Operand &operand,
                         GPRRegister shifter);
 
+  // A vector of pool-allocated x86 labels.
+  std::vector<Label *> CfgNodeLabels;
+
   AssemblerBuffer buffer_;
 };