new classes: special construct stub for derived classs and TDZ for `this`.

src/arm64/full-codegen-arm64.cc

Index: src/arm64/full-codegen-arm64.cc
diff --git a/src/arm64/full-codegen-arm64.cc b/src/arm64/full-codegen-arm64.cc
index 72bd507c9aa5cc739e59e7abdafd8b8083fea30b..c2f022fb9ae5f96a012759654f3bda779b1aa8c2 100644
--- a/src/arm64/full-codegen-arm64.cc
+++ b/src/arm64/full-codegen-arm64.cc
@@ -1517,6 +1517,9 @@ void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy) {
         bool skip_init_check;
         if (var->scope()->DeclarationScope() != scope()->DeclarationScope()) {
           skip_init_check = false;
+        } else if (var->is_this()) {
+          // TODO(dslomov): implement 'this' hole check elimination.
+          skip_init_check = false;
         } else {
           // Check that we always have valid source position.
           DCHECK(var->initializer_position() != RelocInfo::kNoPosition);
@@ -2977,8 +2980,7 @@ void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
 
   RecordJSReturnSite(expr);
 
-  // TODO(dslomov): implement TDZ for `this`.
-  EmitVariableAssignment(super_ref->this_var()->var(), Token::ASSIGN);
+  EmitVariableAssignment(super_ref->this_var()->var(), Token::INIT_CONST);
   context()->Plug(x0);
 }