Better typing and type verification

src/types.cc

Index: src/types.cc
diff --git a/src/types.cc b/src/types.cc
index db92f30c47c05a64c20949fe9801d6e7ab4bc274..f40dc4323ce33264976f85d4ed022d80997fdecb 100644
--- a/src/types.cc
+++ b/src/types.cc
@@ -181,6 +181,7 @@ int TypeImpl<Config>::BitsetType::Lub(i::Map* map) {
     case SHORT_EXTERNAL_STRING_TYPE:
     case SHORT_EXTERNAL_ASCII_STRING_TYPE:
     case SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
+      return kOtherString;
     case INTERNALIZED_STRING_TYPE:
     case ASCII_INTERNALIZED_STRING_TYPE:
     case EXTERNAL_INTERNALIZED_STRING_TYPE:
@@ -189,7 +190,7 @@ int TypeImpl<Config>::BitsetType::Lub(i::Map* map) {
     case SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE:
     case SHORT_EXTERNAL_ASCII_INTERNALIZED_STRING_TYPE:
     case SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
-      return kString;
+      return kInternalizedString;
     case SYMBOL_TYPE:
       return kSymbol;
     case ODDBALL_TYPE: {
@@ -251,6 +252,7 @@ int TypeImpl<Config>::BitsetType::Lub(i::Map* map) {
     case SHARED_FUNCTION_INFO_TYPE:
     case ACCESSOR_PAIR_TYPE:
     case FIXED_ARRAY_TYPE:
+    case BYTE_ARRAY_TYPE:
     case FOREIGN_TYPE:
     case CODE_TYPE:
       return kInternal & kTaggedPtr;