Implement proper scoping for "this" in arrow functions

src/ppc/lithium-codegen-ppc.cc

Index: src/ppc/lithium-codegen-ppc.cc
diff --git a/src/ppc/lithium-codegen-ppc.cc b/src/ppc/lithium-codegen-ppc.cc
index 7b6052c3e624ef89eb678241ef74dbffcfadf5dc..0ee217d77f9757d49dd3a918e2e311b0b08656e9 100644
--- a/src/ppc/lithium-codegen-ppc.cc
+++ b/src/ppc/lithium-codegen-ppc.cc
@@ -119,7 +119,7 @@ bool LCodeGen::GeneratePrologue() {
     // global proxy when called as functions (without an explicit receiver
     // object).
     if (info_->this_has_uses() && info_->strict_mode() == SLOPPY &&
-        !info_->is_native()) {
+        !info_->is_native() && info_->scope()->has_this_declaration()) {
       Label ok;
       int receiver_offset = info_->scope()->num_parameters() * kPointerSize;
       __ LoadP(r5, MemOperand(sp, receiver_offset));
@@ -198,8 +198,9 @@ bool LCodeGen::GeneratePrologue() {
     __ StoreP(r3, MemOperand(fp, StandardFrameConstants::kContextOffset));
     // Copy any necessary parameters into the context.
     int num_parameters = scope()->num_parameters();
-    for (int i = 0; i < num_parameters; i++) {
-      Variable* var = scope()->parameter(i);
+    int first_parameter = scope()->has_this_declaration() ? -1 : 0;
+    for (int i = first_parameter; i < num_parameters; i++) {
+      Variable* var = (i == -1) ? scope()->receiver() : scope()->parameter(i);
       if (var->IsContextSlot()) {
         int parameter_offset = StandardFrameConstants::kCallerSPOffset +
                                (num_parameters - 1 - i) * kPointerSize;