Implement proper scoping for "this" in arrow functions

src/arm64/lithium-codegen-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/arm64/lithium-codegen-arm64.h"
 #include "src/arm64/lithium-gap-resolver-arm64.h"
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 624 matching lines @@
   if (info()->IsOptimizing()) {
     ProfileEntryHookStub::MaybeCallEntryHook(masm_);
 
     // TODO(all): Add support for stop_t FLAG in DEBUG mode.
 
     // 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_->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() * kXRegSize;
       __ Peek(x10, receiver_offset);
       __ JumpIfNotRoot(x10, Heap::kUndefinedValueRootIndex, &ok);
 
       __ Ldr(x10, GlobalObjectMemOperand());
       __ Ldr(x10, FieldMemOperand(x10, GlobalObject::kGlobalProxyOffset));
       __ Poke(x10, receiver_offset);
 
       __ Bind(&ok);
@@ skipping 37 matching lines @@
       __ Push(x1);
       __ CallRuntime(Runtime::kNewFunctionContext, 1);
     }
     RecordSafepoint(Safepoint::kNoLazyDeopt);
     // Context is returned in x0. It replaces the context passed to us. It's
     // saved in the stack and kept live in cp.
     __ Mov(cp, x0);
     __ Str(x0, 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()) {
         Register value = x0;
         Register scratch = x3;
 
         int parameter_offset = StandardFrameConstants::kCallerSPOffset +
             (num_parameters - 1 - i) * kPointerSize;
         // Load parameter from stack.
         __ Ldr(value, MemOperand(fp, parameter_offset));
         // Store it in the context.
         MemOperand target = ContextMemOperand(cp, var->index());
@@ skipping 5348 matching lines @@
   Handle<ScopeInfo> scope_info = instr->scope_info();
   __ Push(scope_info);
   __ Push(ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 
 } }  // namespace v8::internal