Pass closure object as first implicit argument to closure functions.

runtime/vm/intermediate_language_x64.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "lib/error.h"
@@ skipping 904 matching lines @@
 
 void NativeCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT(locs()->temp(0).reg() == RAX);
   ASSERT(locs()->temp(1).reg() == RBX);
   ASSERT(locs()->temp(2).reg() == R10);
   Register result = locs()->out().reg();
 
   // Push the result place holder initialized to NULL.
   __ PushObject(Object::ZoneHandle());
   // Pass a pointer to the first argument in RAX.
-  intptr_t arg_count = argument_count();
-  if (is_native_instance_closure()) {
-    arg_count += 1;
-  }
-  if (!has_optional_parameters() && !is_native_instance_closure()) {
-    __ leaq(RAX, Address(RBP, (1 + arg_count) * kWordSize));
+  if (!function().HasOptionalParameters()) {
+    __ leaq(RAX, Address(RBP, (1 + function().NumParameters()) * kWordSize));
   } else {
     __ leaq(RAX,
             Address(RBP, ParsedFunction::kFirstLocalSlotIndex * kWordSize));
   }
   __ movq(RBX, Immediate(reinterpret_cast<uword>(native_c_function())));
-  __ movq(R10, Immediate(arg_count));
+  __ movq(R10, Immediate(NativeArguments::ComputeArgcTag(function())));
   compiler->GenerateCall(token_pos(),
                          &StubCode::CallNativeCFunctionLabel(),
                          PcDescriptors::kOther,
                          locs());
   __ popq(result);
 }
 
 
 static bool CanBeImmediateIndex(Value* index) {
   if (!index->definition()->IsConstant()) return false;
@@ skipping 1414 matching lines @@
 
 void ShiftMintOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   UNIMPLEMENTED();
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64