Compute the swap temporary to not clash with parameter names.

dart/lib/compiler/implementation/ssa/codegen.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.
 
 class SsaCodeGeneratorTask extends CompilerTask {
   final JavaScriptBackend backend;
   SsaCodeGeneratorTask(JavaScriptBackend backend)
       : this.backend = backend,
         super(backend.compiler);
   String get name() => 'SSA code generator';
@@ skipping 1057 matching lines @@
         }
       }
 
       // Check if we have a cycle.
       String current = worklist.removeLast();
       // If [current] is used as a source, and the assignment has been
       // done, we are done with this variable. Otherwise there is a
       // cycle that we break by using a temporary name.
       if (currentLocation[current] !== null
           && current != currentLocation[initialValue[current]]) {
-        String tempName = VariableNames.SWAP_TEMP;
+        String tempName = variableNames.swapTemp;
         emitAssignment(tempName, current);
         currentLocation[current] = tempName;
         // [current] can now be safely updated. Copies of [current]
         // will now use [tempName].
         ready.add(current);
       }
     }
   }
 
   void assignPhisOfSuccessors(HBasicBlock node) {
@@ skipping 1584 matching lines @@
       startBailoutSwitch();
     }
   }
 
   void endLabeledBlock(HLabeledBlockInformation labeledBlockInfo) {
     if (labeledBlockInfo.body.start.hasGuards()) {
       endBailoutSwitch();
     }
   }
 }