[es6] generate rest parameters correctly for subclass constructors

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 a219ac05af176b01247d56c5fae31ac8babb2618..786d5fee967af9e8f5fa48ed73967ff2cc7dce85 100644
--- a/src/arm64/full-codegen-arm64.cc
+++ b/src/arm64/full-codegen-arm64.cc
@@ -241,6 +241,11 @@ void FullCodeGenerator::Generate() {
     }
   }
 
+  ArgumentsAccessStub::HasNewTarget has_new_target =
+      IsSubclassConstructor(info->function()->kind())
+          ? ArgumentsAccessStub::HAS_NEW_TARGET
+          : ArgumentsAccessStub::NO_NEW_TARGET;
+
   // Possibly allocate RestParameters
   int rest_index;
   Variable* rest_param = scope()->rest_parameter(&rest_index);
@@ -249,6 +254,11 @@ void FullCodeGenerator::Generate() {
 
     int num_parameters = info->scope()->num_parameters();
     int offset = num_parameters * kPointerSize;
+    if (has_new_target == ArgumentsAccessStub::HAS_NEW_TARGET) {
+      --num_parameters;
+      ++rest_index;
+    }
+
     __ Add(x3, fp, StandardFrameConstants::kCallerSPOffset + offset);
     __ Mov(x2, Smi::FromInt(num_parameters));
     __ Mov(x1, Smi::FromInt(rest_index));
@@ -281,10 +291,6 @@ void FullCodeGenerator::Generate() {
     //   function, receiver address, parameter count.
     // The stub will rewrite receiver and parameter count if the previous
     // stack frame was an arguments adapter frame.
-    ArgumentsAccessStub::HasNewTarget has_new_target =
-        IsSubclassConstructor(info->function()->kind())
-            ? ArgumentsAccessStub::HAS_NEW_TARGET
-            : ArgumentsAccessStub::NO_NEW_TARGET;
     ArgumentsAccessStub::Type type;
     if (is_strict(language_mode()) || !is_simple_parameter_list()) {
       type = ArgumentsAccessStub::NEW_STRICT;