Pass closure object as first implicit argument to closure functions.

runtime/vm/intermediate_language.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/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 1823 matching lines @@
   } else {
     __ CompareRegisters(left.reg(), right.reg());
   }
 
   Condition true_condition = (kind() == Token::kEQ_STRICT) ? EQUAL : NOT_EQUAL;
   branch->EmitBranchOnCondition(compiler, true_condition);
 }
 
 
 void ClosureCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  // The arguments to the stub include the closure.  The arguments
-  // descriptor describes the closure's arguments (and so does not include
-  // the closure).
+  // The arguments to the stub include the closure, as does the arguments
+  // descriptor.
   Register temp_reg = locs()->temp(0).reg();
   int argument_count = ArgumentCount();
   const Array& arguments_descriptor =
-      DartEntry::ArgumentsDescriptor(argument_count - 1,
-                                         argument_names());
+      DartEntry::ArgumentsDescriptor(argument_count, argument_names());
   __ LoadObject(temp_reg, arguments_descriptor);
   compiler->GenerateDartCall(deopt_id(),
                              token_pos(),
                              &StubCode::CallClosureFunctionLabel(),
                              PcDescriptors::kOther,
                              locs());
   __ Drop(argument_count);
 }
 
 
@@ skipping 784 matching lines @@
       return Array::length_offset();
     default:
       UNREACHABLE();
       return -1;
   }
 }
 
 #undef __
 
 }  // namespace dart