Use a reusable handle in SubString instead of creating one as this path is now used when creating S…

runtime/vm/object.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_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 6557 matching lines @@
                                    intptr_t start,
                                    intptr_t end,
                                    Heap::Space space = Heap::kNew);
 
   static RawString* SubString(const String& str,
                               intptr_t begin_index,
                               Heap::Space space = Heap::kNew);
   static RawString* SubString(const String& str,
                               intptr_t begin_index,
                               intptr_t length,
+                              Heap::Space space = Heap::kNew) {
+    return SubString(Thread::Current(), str, begin_index, length, space);
+  }
+  static RawString* SubString(Thread* thread,
+                              const String& str,
+                              intptr_t begin_index,
+                              intptr_t length,
                               Heap::Space space = Heap::kNew);
 
   static RawString* Transform(int32_t (*mapping)(int32_t ch),
                               const String& str,
                               Heap::Space space = Heap::kNew);
 
   static RawString* ToUpperCase(const String& str,
                                 Heap::Space space = Heap::kNew);
   static RawString* ToLowerCase(const String& str,
                                 Heap::Space space = Heap::kNew);
@@ skipping 1919 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_