Do not use new struct type where unnecessary.

src/ast/ast-types.cc

Index: src/ast/ast-types.cc
diff --git a/src/ast/ast-types.cc b/src/ast/ast-types.cc
index 9e14730c97693e037a95a65a967a10ad4de812c9..8ff1d883519176299c7ef3f7688caaee65bc131f 100644
--- a/src/ast/ast-types.cc
+++ b/src/ast/ast-types.cc
@@ -302,16 +302,13 @@ AstType::bitset AstBitsetType::Lub(i::Map* map) {
     case FILLER_TYPE:
     case ACCESS_CHECK_INFO_TYPE:
     case INTERCEPTOR_INFO_TYPE:
-    case CALL_HANDLER_INFO_TYPE:
     case PROMISE_RESOLVE_THENABLE_JOB_INFO_TYPE:
     case PROMISE_REACTION_JOB_INFO_TYPE:
     case FUNCTION_TEMPLATE_INFO_TYPE:
     case OBJECT_TEMPLATE_INFO_TYPE:
     case ALLOCATION_MEMENTO_TYPE:
-    case TYPE_FEEDBACK_INFO_TYPE:
     case ALIASED_ARGUMENTS_ENTRY_TYPE:
     case DEBUG_INFO_TYPE:
-    case BREAK_POINT_INFO_TYPE:
     case STACK_FRAME_INFO_TYPE:
     case CELL_TYPE:
     case WEAK_CELL_TYPE:
@@ -319,7 +316,10 @@ AstType::bitset AstBitsetType::Lub(i::Map* map) {
     case TUPLE2_TYPE:
     case TUPLE3_TYPE:
     case CONTEXT_EXTENSION_TYPE:
-    case CONSTANT_ELEMENTS_PAIR_TYPE:
+    case PADDING_TYPE_1:
+    case PADDING_TYPE_2:
+    case PADDING_TYPE_3:
+    case PADDING_TYPE_4:
       UNREACHABLE();
       return kNone;
   }