First cut at API for ES6 ArrayBuffers

src/contexts.h

Index: src/contexts.h
diff --git a/src/contexts.h b/src/contexts.h
index abeb8121cbf515cbf3ede188792fdc6306fcee77..0024e13d6bbe256f71136fc36ab166e764a3e149 100644
--- a/src/contexts.h
+++ b/src/contexts.h
@@ -123,6 +123,7 @@ enum BindingFlags {
   V(GLOBAL_EVAL_FUN_INDEX, JSFunction, global_eval_fun) \
   V(INSTANTIATE_FUN_INDEX, JSFunction, instantiate_fun) \
   V(CONFIGURE_INSTANCE_FUN_INDEX, JSFunction, configure_instance_fun) \
+  V(ARRAY_BUFFER_FUN_INDEX, JSFunction, array_buffer_fun) \
   V(FUNCTION_MAP_INDEX, Map, function_map) \
   V(STRICT_MODE_FUNCTION_MAP_INDEX, Map, strict_mode_function_map) \
   V(FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX, Map, function_without_prototype_map) \
@@ -276,6 +277,7 @@ class Context: public FixedArray {
     GLOBAL_EVAL_FUN_INDEX,
     INSTANTIATE_FUN_INDEX,
     CONFIGURE_INSTANCE_FUN_INDEX,
+    ARRAY_BUFFER_FUN_INDEX,
     MESSAGE_LISTENERS_INDEX,
     MAKE_MESSAGE_FUN_INDEX,
     GET_STACK_TRACE_LINE_INDEX,