Fix simulator build failure in profiler.cc

runtime/vm/profiler.cc

 // Copyright (c) 2013, 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 "platform/address_sanitizer.h"
 #include "platform/memory_sanitizer.h"
 #include "platform/utils.h"
 
 #include "vm/allocation.h"
 #include "vm/atomic.h"
@@ skipping 932 matching lines @@
 
   const bool in_dart_code = thread->IsExecutingDartCode();
 
   uintptr_t sp = 0;
   uintptr_t fp = state.fp;
   uintptr_t pc = state.pc;
 #if defined(USING_SIMULATOR)
   Simulator* simulator = NULL;
 #endif
 
+  ASSERT(thread != NULL);
+  Isolate* isolate = thread->isolate();
+
   if (in_dart_code) {
     // If we're in Dart code, use the Dart stack pointer.
 #if defined(USING_SIMULATOR)
     simulator = isolate->simulator();
     sp = simulator->get_register(SPREG);
     fp = simulator->get_register(FPREG);
     pc = simulator->get_pc();
 #else
     sp = state.dsp;
 #endif
   } else {
     // If we're in runtime code, use the C stack pointer.
     sp = state.csp;
   }
 
   if (!InitialRegisterCheck(pc, fp, sp)) {
     return;
   }
 
-  ASSERT(thread != NULL);
-  Isolate* isolate = thread->isolate();
   if (!CheckIsolate(isolate)) {
     return;
   }
 
   if (!thread->IsMutatorThread()) {
     // Not a mutator thread.
     // TODO(johnmccutchan): Profile all threads with an isolate.
     return;
   }
 
@@ skipping 274 matching lines @@
                                                uword pc) {
   return vm_isolate->heap()->CodeContains(pc)
          || isolate->heap()->CodeContains(pc);
 }
 
 
 ProcessedSampleBuffer::ProcessedSampleBuffer() {
 }
 
 }  // namespace dart