[turbofan] Introduce new Select operator to improve bounds checking.

src/compiler/common-operator.h

Index: src/compiler/common-operator.h
diff --git a/src/compiler/common-operator.h b/src/compiler/common-operator.h
index 31c3d129e2257a8b553a6955e1a09333b1d99246..355269cd5d2ec24e542a9031f8130a6537fb7423 100644
--- a/src/compiler/common-operator.h
+++ b/src/compiler/common-operator.h
@@ -33,6 +33,30 @@ std::ostream& operator<<(std::ostream&, BranchHint);
 BranchHint BranchHintOf(const Operator* const);
 
 
+class SelectParameters FINAL {
+ public:
+  explicit SelectParameters(MachineType type,
+                            BranchHint hint = BranchHint::kNone)
+      : type_(type), hint_(hint) {}
+
+  MachineType type() const { return type_; }
+  BranchHint hint() const { return hint_; }
+
+ private:
+  const MachineType type_;
+  const BranchHint hint_;
+};
+
+bool operator==(SelectParameters const&, SelectParameters const&);
+bool operator!=(SelectParameters const&, SelectParameters const&);
+
+size_t hash_value(SelectParameters const& p);
+
+std::ostream& operator<<(std::ostream&, SelectParameters const& p);
+
+SelectParameters const& SelectParametersOf(const Operator* const);
+
+
 // Flag that describes how to combine the current environment with
 // the output of a node to obtain a framestate for lazy bailout.
 class OutputFrameStateCombine {
@@ -157,6 +181,7 @@ class CommonOperatorBuilder FINAL : public ZoneObject {
   const Operator* NumberConstant(volatile double);
   const Operator* HeapConstant(const Unique<HeapObject>&);
 
+  const Operator* Select(MachineType, BranchHint = BranchHint::kNone);
   const Operator* Phi(MachineType type, int arguments);
   const Operator* EffectPhi(int arguments);
   const Operator* ValueEffect(int arguments);