Make RegExp's constructor non-const.

sdk/lib/_internal/compiler/implementation/ssa/variable_allocator.dart

 // 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.
 
 part of ssa;
 
 /**
  * The [LiveRange] class covers a range where an instruction is live.
  */
 class LiveRange {
@@ skipping 427 matching lines @@
 
 /**
  * Allocates variable names for instructions, making sure they don't collide.
  */
 class VariableNamer {
   final VariableNames names;
   final Set<String> usedNames;
   final Map<Element, String> parameterNames;
   final List<String> freeTemporaryNames;
   int temporaryIndex = 0;
+  static final RegExp regexp = new RegExp('t[0-9]+');
 
   VariableNamer(LiveEnvironment environment, this.names, this.parameterNames)
     : usedNames = new Set<String>(),
       freeTemporaryNames = new List<String>() {
     // [VariableNames.swapTemp] is used when there is a cycle in a copy handler.
     // Therefore we make sure no one uses it.
     usedNames.add(names.swapTemp);
     // [VariableNames.stateName] is being used throughout a bailout function.
     // Whenever a bailout-target is reached we set the state-variable to 0. We
     // must therefore not have any local variable that could clash with the
@@ skipping 85 matching lines @@
     names.ownName[instruction] = name;
     return name;
   }
 
   /**
    * Frees [instruction]'s name so it can be used for other instructions.
    */
   void freeName(HInstruction instruction) {
     String ownName = names.ownName[instruction];
     if (ownName != null) {
-      RegExp regexp = const RegExp('t[0-9]+');
       // We check if we have already looked for temporary names
       // because if we haven't, chances are the temporary we allocate
       // in this block can match a phi with the same name in the
       // successor block.
       if (temporaryIndex != 0 && regexp.hasMatch(ownName)) {
         freeTemporaryNames.addLast(ownName);
       }
       usedNames.remove(ownName);
     }
   }
@@ skipping 111 matching lines @@
       if (!needsName(input)) {
         names.addAssignment(predecessor, input, phi);
       } else {
         names.addCopy(predecessor, input, phi);
       }
     }
 
     namer.allocateName(phi);
   }
 }