[turbofan] Add support for deferred code.

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 c5a8d7ee691a40e5f54c7b5960237521dfe169f0..c65e1a7db5abbe8cc0078bc8bba3a416729e95fa 100644
--- a/src/compiler/common-operator.h
+++ b/src/compiler/common-operator.h
@@ -23,6 +23,16 @@ struct CommonOperatorBuilderImpl;
 class Operator;
 
 
+// Prediction hint for branches.
+enum class BranchHint : uint8_t { kNone, kTrue, kFalse };
+
+inline size_t hash_value(BranchHint hint) { return static_cast<size_t>(hint); }
+
+std::ostream& operator<<(std::ostream&, BranchHint);
+
+BranchHint BranchHintOf(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 {
@@ -123,7 +133,7 @@ class CommonOperatorBuilder FINAL {
 
   const Operator* Dead();
   const Operator* End();
-  const Operator* Branch();
+  const Operator* Branch(BranchHint = BranchHint::kNone);
   const Operator* IfTrue();
   const Operator* IfFalse();
   const Operator* Throw();