fix cpp11 compile errors

runtime/vm/handles.h

 // 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.
 
 #ifndef VM_HANDLES_H_
 #define VM_HANDLES_H_
 
 #include "vm/allocation.h"
 #include "vm/flags.h"
 #include "vm/os.h"
@@ skipping 233 matching lines @@
                                  kVMHandlesPerChunk,
                                  kOffsetOfRawPtr> {
  public:
   static const int kOffsetOfRawPtrInHandle = kOffsetOfRawPtr;
 
   VMHandles() : Handles<kVMHandleSizeInWords,
                         kVMHandlesPerChunk,
                         kOffsetOfRawPtr>() {
 #ifdef DEBUG
     if (FLAG_trace_handles) {
-      OS::PrintErr("*** Starting a new VM handle block 0x%"Px"\n",
+      OS::PrintErr("*** Starting a new VM handle block 0x%" Px "\n",
                    reinterpret_cast<intptr_t>(this));
     }
 #endif
   }
   ~VMHandles();
 
   // Visit all object pointers stored in the various handles.
   void VisitObjectPointers(ObjectPointerVisitor* visitor);
 
   // Allocates a handle in the current handle scope. This handle is valid only
@@ skipping 76 matching lines @@
 };
 #endif  // defined(DEBUG)
 
 // Macro to start a no handles scope in the code.
 #define NOHANDLESCOPE(isolate)                                                 \
     dart::NoHandleScope no_vm_internal_handles_scope_(isolate);
 
 }  // namespace dart
 
 #endif  // VM_HANDLES_H_