Implement proper scoping for "this" in arrow functions

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 c871d03b3aa73e01482c6ec293b58558b04ad7a9..8dccf8465bf5881fb31e67b54f17d9404d4d0ef8 100644
--- a/src/arm64/full-codegen-arm64.cc
+++ b/src/arm64/full-codegen-arm64.cc
@@ -124,7 +124,8 @@ void FullCodeGenerator::Generate() {
   // Sloppy mode functions and builtins need to replace the receiver with the
   // global proxy when called as functions (without an explicit receiver
   // object).
-  if (info->strict_mode() == SLOPPY && !info->is_native()) {
+  if (info->strict_mode() == SLOPPY && !info->is_native() &&
+      info->scope()->has_this_declaration()) {
     Label ok;
     int receiver_offset = info->scope()->num_parameters() * kXRegSize;
     __ Peek(x10, receiver_offset);
@@ -216,8 +217,9 @@ void FullCodeGenerator::Generate() {
     __ Str(x0, MemOperand(fp, StandardFrameConstants::kContextOffset));
     // Copy any necessary parameters into the context.
     int num_parameters = info->scope()->num_parameters();
-    for (int i = 0; i < num_parameters; i++) {
-      Variable* var = scope()->parameter(i);
+    int first_parameter = info->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;