[Interpreter] Adds support for with statement to interpreter.

src/interpreter/bytecode-generator.cc

Index: src/interpreter/bytecode-generator.cc
diff --git a/src/interpreter/bytecode-generator.cc b/src/interpreter/bytecode-generator.cc
index 4ef0506a12388cf0f534058b33b98e21f3689169..90c2b81e47133db764fc8c99ffbd4ea0ae0e582e 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -859,7 +859,10 @@ void BytecodeGenerator::VisitReturnStatement(ReturnStatement* stmt) {
 
 
 void BytecodeGenerator::VisitWithStatement(WithStatement* stmt) {
-  UNIMPLEMENTED();
+  VisitForAccumulatorValue(stmt->expression());
+  builder()->CastAccumulatorToJSObject();
+  VisitNewLocalWithContext();
+  VisitInScope(stmt->statement(), stmt->scope());
 }
 
 
@@ -2363,6 +2366,19 @@ void BytecodeGenerator::VisitNewLocalBlockContext(Scope* scope) {
   execution_result()->SetResultInAccumulator();
 }
 
+void BytecodeGenerator::VisitNewLocalWithContext() {
+  AccumulatorResultScope accumulator_execution_result(this);
+
+  register_allocator()->PrepareForConsecutiveAllocations(2);
+  Register extension_object = register_allocator()->NextConsecutiveRegister();
+  Register closure = register_allocator()->NextConsecutiveRegister();
+
+  builder()->StoreAccumulatorInRegister(extension_object);
+  VisitFunctionClosureForContext();
+  builder()->StoreAccumulatorInRegister(closure).CallRuntime(
+      Runtime::kPushWithContext, extension_object, 2);
+  execution_result()->SetResultInAccumulator();
+}
 
 void BytecodeGenerator::VisitNewLocalCatchContext(Variable* variable) {
   AccumulatorResultScope accumulator_execution_result(this);
@@ -2458,6 +2474,12 @@ void BytecodeGenerator::VisitFunctionClosureForContext() {
                           Context::NATIVE_CONTEXT_INDEX)
         .StoreAccumulatorInRegister(native_context)
         .LoadContextSlot(native_context, Context::CLOSURE_INDEX);
+  } else if (closure_scope->is_eval_scope()) {

[mythria, 2016/02/01 16:14:42]

Turbofan never hits this. I implemented this from full-codegen:
https://code.google.com/p/chromium/codesearch#chromium/src/v8/src/full-codege...

I think I understood the comment, but could you please check if I am doing it
correct. I am never entirely sure about contexts. All tests in test262 pass, so
it might be correct :) We hit this case when we have with within eval. 

[rmcilroy, 2016/02/02 17:05:22]

This looks right to me, thanks!

+    // Contexts created by a call to eval have the same closure as the
+    // context calling eval, not the anonymous closure containing the eval
+    // code. Fetch it from the context.
+    builder()->LoadContextSlot(execution_context()->reg(),
+                               Context::CLOSURE_INDEX);
   } else {
     DCHECK(closure_scope->is_function_scope());
     builder()->LoadAccumulatorWithRegister(Register::function_closure());