PPC: [es6] generate rest parameters correctly for subclass constructors

commit bef80fcf

Original commit message:
BUG=v8:3977
R=dslomov@chromium.org, arv@chromium.org
LOG=N

R=mbrandy@us.ibm.com, svenpanne@chromium.org, danno@chromium.org, jkummerow@chromium.org

Review URL: https://codereview.chromium.org/1018043008

Cr-Commit-Position: refs/heads/master@{#27390}

src/ppc/full-codegen-ppc.cc

@@ -245,6 +245,11 @@ 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);
@@ -253,6 +258,11 @@ 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;
+    }
+
     __ addi(r6, fp, Operand(StandardFrameConstants::kCallerSPOffset + offset));
     __ mov(r5, Operand(Smi::FromInt(num_parameters)));
     __ mov(r4, Operand(Smi::FromInt(rest_index)));
@@ -285,10 +295,6 @@ void FullCodeGenerator::Generate() {
     //   function, receiver address, parameter count.
     // The stub will rewrite receiever 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;