Add HasSSATemp and an assert to ssa_temp_idnex setter.

runtime/vm/intermediate_language.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_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 2095 matching lines @@
  public:
   Definition() : temp_index_(-1), ssa_temp_index_(-1) { }
 
   virtual bool IsDefinition() const { return true; }
   virtual Definition* AsDefinition() { return this; }
 
   intptr_t temp_index() const { return temp_index_; }
   void set_temp_index(intptr_t index) { temp_index_ = index; }
 
   intptr_t ssa_temp_index() const { return ssa_temp_index_; }
-  void set_ssa_temp_index(intptr_t index) { ssa_temp_index_ = index; }
+  void set_ssa_temp_index(intptr_t index) {
+    ASSERT(index >= 0);
+    ssa_temp_index_ = index;
+  }
+  bool HasSSATemp() const { return ssa_temp_index_ >= 0; }
 
  private:
   intptr_t temp_index_;
   intptr_t ssa_temp_index_;
 
   DISALLOW_COPY_AND_ASSIGN(Definition);
 };
 
 
 Definition* UseVal::definition() const {
@@ skipping 406 matching lines @@
   const GrowableArray<BlockEntryInstr*>& block_order_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_