Rename NativeReceiver to NativeArg0 as this method is used not necessarily

runtime/vm/native_arguments.h

 // 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.
 
 #ifndef VM_NATIVE_ARGUMENTS_H_
 #define VM_NATIVE_ARGUMENTS_H_
 
 #include "platform/assert.h"
 #include "vm/globals.h"
 #include "vm/handles_impl.h"
@@ skipping 79 matching lines @@
   RawObject* ArgAt(int index) const {
     ASSERT((index >= 0) && (index < ArgCount()));
     return (*argv_)[-index];
   }
 
   int NativeArgCount() const {
     int function_bits = FunctionBits::decode(argc_tag_);
     return ArgCount() - NumHiddenArgs(function_bits);
   }
 
-  RawObject* NativeReceiver() const {
-    ASSERT(ToInstanceFunction());
-    return NativeArg0();
+  RawObject* NativeArg0() const {
+    int function_bits = FunctionBits::decode(argc_tag_);
+    if (function_bits == (kClosureFunctionBit | kInstanceFunctionBit)) {
+      // Retrieve the receiver from the context.
+      const Context& context = Context::Handle(isolate_->top_context());
+      return context.At(0);
+    }
+    return ArgAt(NumHiddenArgs(function_bits));
   }
 
   RawObject* NativeArgAt(int index) const {
     ASSERT((index >= 0) && (index < NativeArgCount()));
     if (index == 0) {
       return NativeArg0();
     }
     int function_bits = FunctionBits::decode(argc_tag_);
     const int actual_index = index + NumHiddenArgs(function_bits);
     return ArgAt(actual_index);
@@ skipping 81 matching lines @@
     // For static closure functions, the closure at index 0 is hidden.
     // In the instance closure function case, the receiver is accessed from
     // the context and the closure at index 0 is hidden, so the apparent
     // argument count remains unchanged.
     if (function_bits == kClosureFunctionBit) {
       return 1;
     }
     return 0;
   }
 
-  RawObject* NativeArg0() const {
-    int function_bits = FunctionBits::decode(argc_tag_);
-    if (function_bits == (kClosureFunctionBit | kInstanceFunctionBit)) {
-      // Retrieve the receiver from the context.
-      const Context& context = Context::Handle(isolate_->top_context());
-      return context.At(0);
-    }
-    return ArgAt(NumHiddenArgs(function_bits));
-  }
-
   Isolate* isolate_;  // Current isolate pointer.
   int argc_tag_;  // Encodes argument count and invoked native call type.
   RawObject*(*argv_)[];  // Pointer to an array of arguments to runtime call.
   RawObject** retval_;  // Pointer to the return value area.
 };
 
 }  // namespace dart
 
 #endif  // VM_NATIVE_ARGUMENTS_H_