Use a dictionary-mode code cache on the map rather than a dual system.

src/log.h

Index: src/log.h
diff --git a/src/log.h b/src/log.h
index 0fc7388d851fac6cf9d4b851f92af0a97041edd6..96e6f1a4ca976e249d4aff6c4e79c31762fbc6d4 100644
--- a/src/log.h
+++ b/src/log.h
@@ -100,12 +100,9 @@ struct TickSample;
   V(CALL_MEGAMORPHIC_TAG, "CallMegamorphic")                             \
   V(CALL_MISS_TAG, "CallMiss")                                           \
   V(CALL_NORMAL_TAG, "CallNormal")                                       \
-  V(CALL_PRE_MONOMORPHIC_TAG, "CallPreMonomorphic")                      \
   V(LOAD_INITIALIZE_TAG, "LoadInitialize")                               \
-  V(LOAD_PREMONOMORPHIC_TAG, "LoadPreMonomorphic")                       \
   V(LOAD_MEGAMORPHIC_TAG, "LoadMegamorphic")                             \
   V(STORE_INITIALIZE_TAG, "StoreInitialize")                             \
-  V(STORE_PREMONOMORPHIC_TAG, "StorePreMonomorphic")                     \
   V(STORE_GENERIC_TAG, "StoreGeneric")                                   \
   V(STORE_MEGAMORPHIC_TAG, "StoreMegamorphic")                           \
   V(KEYED_CALL_DEBUG_BREAK_TAG, "KeyedCallDebugBreak")                   \
@@ -114,7 +111,6 @@ struct TickSample;
   V(KEYED_CALL_MEGAMORPHIC_TAG, "KeyedCallMegamorphic")                  \
   V(KEYED_CALL_MISS_TAG, "KeyedCallMiss")                                \
   V(KEYED_CALL_NORMAL_TAG, "KeyedCallNormal")                            \
-  V(KEYED_CALL_PRE_MONOMORPHIC_TAG, "KeyedCallPreMonomorphic")           \
   V(CALLBACK_TAG, "Callback")                                            \
   V(EVAL_TAG, "Eval")                                                    \
   V(FUNCTION_TAG, "Function")                                            \