Add support for leaf runtime calls

vm/runtime_entry_ia32.cc

 // Copyright (c) 2011, 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"
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/runtime_entry.h"
 
 #include "vm/assembler.h"
 #include "vm/stub_code.h"
 
 namespace dart {
 
 #define __ assembler->
 
 
 // Generate code to call into the stub which will call the runtime
 // function. Input for the stub is as follows:
 //   ESP : points to the arguments and return value array.
 //   ECX : address of the runtime function to call.
 //   EDX : number of arguments to the call.
 void RuntimeEntry::Call(Assembler* assembler) const {
   __ movl(ECX, Immediate(GetEntryPoint()));
   __ movl(EDX, Immediate(argument_count()));
-  __ call(&StubCode::CallToRuntimeLabel());
+  if (is_leaf()) {
+    __ call(&StubCode::CallToLeafRuntimeLabel());
+  } else {
+    __ call(&StubCode::CallToRuntimeLabel());
+  }
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32