[Interpreter] Adds support for const/let variables to interpreter.

src/compiler/bytecode-graph-builder.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/bytecode-graph-builder.h"
 
 #include "src/compiler/bytecode-branch-analysis.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/operator-properties.h"
 #include "src/interpreter/bytecodes.h"
@@ skipping 1747 matching lines @@
     const interpreter::BytecodeArrayIterator& iterator) {
   BuildJumpIfEqual(jsgraph()->UndefinedConstant());
 }
 
 
 void BytecodeGraphBuilder::VisitJumpIfUndefinedConstantWide(
     const interpreter::BytecodeArrayIterator& iterator) {
   BuildJumpIfEqual(jsgraph()->UndefinedConstant());
 }
 
+void BytecodeGraphBuilder::VisitJumpIfHole(
+    const interpreter::BytecodeArrayIterator& iterator) {
+  BuildJumpIfEqual(jsgraph()->TheHoleConstant());
+}
+
+void BytecodeGraphBuilder::VisitJumpIfNotHole(
+    const interpreter::BytecodeArrayIterator& iterator) {
+  Node* accumulator = environment()->LookupAccumulator();
+  Node* condition = NewNode(javascript()->StrictEqual(), accumulator,
+                            jsgraph()->TheHoleConstant());
+  Node* node =
+      NewNode(common()->Select(MachineRepresentation::kTagged), condition,
+              jsgraph()->FalseConstant(), jsgraph()->TrueConstant());
+  BuildConditionalJump(node);
+}
 
 void BytecodeGraphBuilder::VisitReturn(
     const interpreter::BytecodeArrayIterator& iterator) {
   Node* control =
       NewNode(common()->Return(), environment()->LookupAccumulator());
   UpdateControlDependencyToLeaveFunction(control);
   set_environment(nullptr);
 }
 
 
@@ skipping 324 matching lines @@
 
 void BytecodeGraphBuilder::UpdateControlDependencyToLeaveFunction(Node* exit) {
   if (environment()->IsMarkedAsUnreachable()) return;
   environment()->MarkAsUnreachable();
   exit_controls_.push_back(exit);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8