[interpreter] Add CreateFunctionContext bytecode

src/interpreter/bytecode-array-builder.h

 // 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.
 
 #ifndef V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
 #define V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
 
 #include "src/ast/ast.h"
 #include "src/interpreter/bytecode-array-writer.h"
 #include "src/interpreter/bytecode-register-allocator.h"
@@ skipping 117 matching lines @@
                                        TypeofMode typeof_mode);
 
   // Store value in the accumulator into the variable with |name|.
   BytecodeArrayBuilder& StoreLookupSlot(const Handle<String> name,
                                         LanguageMode language_mode);
 
   // Create a new closure for the SharedFunctionInfo.
   BytecodeArrayBuilder& CreateClosure(Handle<SharedFunctionInfo> shared_info,
                                       int flags);
 
+  // Create a new context with size |slots| in the accumulator.

[rmcilroy, 2016/08/03 10:58:14]

nit - drop the "in the accumulator" (slight confusion that it sounds like
|slots| should be in the accumulator, and the default is for results to be in
the accumulator.

[klaasb, 2016/08/03 12:28:16]

Done.

+  BytecodeArrayBuilder& CreateFunctionContext(int slots);
+
   // Create a new arguments object in the accumulator.
   BytecodeArrayBuilder& CreateArguments(CreateArgumentsType type);
 
   // Literals creation.  Constant elements should be in the accumulator.
   BytecodeArrayBuilder& CreateRegExpLiteral(Handle<String> pattern,
                                             int literal_index, int flags);
   BytecodeArrayBuilder& CreateArrayLiteral(Handle<FixedArray> constant_elements,
                                            int literal_index, int flags);
   BytecodeArrayBuilder& CreateObjectLiteral(
       Handle<FixedArray> constant_properties, int literal_index, int flags);
@@ skipping 235 matching lines @@
   BytecodeSourceInfo latest_source_info_;
 
   DISALLOW_COPY_AND_ASSIGN(BytecodeArrayBuilder);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_