Add Function based profile tree

runtime/vm/instructions_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/cpu.h"
 #include "vm/instructions.h"
 #include "vm/object.h"
@@ skipping 55 matching lines @@
   *reinterpret_cast<uint32_t*>(start() + 1) = target - start() - kLengthInBytes;
   CPU::FlushICache(start() + 1, kWordSize);
 }
 
 
 const int* ShortCallPattern::pattern() const {
   static const int kCallPattern[kLengthInBytes] = {0xE8, -1, -1, -1, -1};
   return kCallPattern;
 }
 
+
+const int* ReturnPattern::pattern() const {
+  static const int kReturnPattern[kLengthInBytes] = { 0xC3 };
+  return kReturnPattern;
+}
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64