arrange to create prototypes for generators

src/contexts.h

Index: src/contexts.h
diff --git a/src/contexts.h b/src/contexts.h
index a0ba2f7eb5f577efed6e7da90a4f63dac0977d27..fd6c8c0959562b75f2b1c98dbdc0f0741bca65fe 100644
--- a/src/contexts.h
+++ b/src/contexts.h
@@ -165,6 +165,11 @@ enum BindingFlags {
   V(PROXY_ENUMERATE_INDEX, JSFunction, proxy_enumerate) \
   V(OBSERVERS_NOTIFY_CHANGE_INDEX, JSFunction, observers_notify_change) \
   V(OBSERVERS_DELIVER_CHANGES_INDEX, JSFunction, observers_deliver_changes) \
+  V(GENERATOR_FUNCTION_MAP_INDEX, Map, generator_function_map) \
+  V(STRICT_MODE_GENERATOR_FUNCTION_MAP_INDEX, Map, \
+    strict_mode_generator_function_map) \
+  V(GENERATOR_ITERATOR_PROTOTYPE_MAP_INDEX, Map, \
+    generator_iterator_prototype_map) \
   V(RANDOM_SEED_INDEX, ByteArray, random_seed)
 
 // JSFunctions are pairs (context, function code), sometimes also called
@@ -295,6 +300,9 @@ class Context: public FixedArray {
     PROXY_ENUMERATE_INDEX,
     OBSERVERS_NOTIFY_CHANGE_INDEX,
     OBSERVERS_DELIVER_CHANGES_INDEX,
+    GENERATOR_FUNCTION_MAP_INDEX,
+    STRICT_MODE_GENERATOR_FUNCTION_MAP_INDEX,
+    GENERATOR_ITERATOR_PROTOTYPE_MAP_INDEX,
     RANDOM_SEED_INDEX,
 
     // Properties from here are treated as weak references by the full GC.