Use only single characters for ssa types.

lib/compiler/implementation/ssa/tracer.dart

 // 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.
 
 #library('tracer');
 
 #import('dart:io');
 #import('ssa.dart');
 #import('../leg.dart');
 
@@ skipping 149 matching lines @@
   visit(HInstruction node) => node.accept(this);
 
   visitBasicBlock(HBasicBlock node) {
     unreachable();
   }
 
   String temporaryId(HInstruction instruction) {
     String prefix;
     HType type = instruction.propagatedType;
     switch (type) {
-      case HType.MUTABLE_ARRAY: prefix = 'a'; break;
-      case HType.READABLE_ARRAY: prefix = 'roa'; break;
+      case HType.MUTABLE_ARRAY: prefix = 'm'; break;
+      case HType.READABLE_ARRAY: prefix = 'a'; break;
       case HType.BOOLEAN: prefix = 'b'; break;
       case HType.INTEGER: prefix = 'i'; break;
       case HType.DOUBLE: prefix = 'd'; break;
       case HType.NUMBER: prefix = 'n'; break;
       case HType.STRING: prefix = 's'; break;
       case HType.UNKNOWN: prefix = 'v'; break;
       case HType.CONFLICTING: prefix = 'c'; break;
-      case HType.STRING_OR_ARRAY: prefix = 'sa'; break;
+      case HType.STRING_OR_ARRAY: prefix = 'r'; break;
       default: unreachable();
     }
     return "$prefix${instruction.id}";
   }
 
   String visitBoolify(HBoolify node) {
     return "Boolify: ${temporaryId(node.inputs[0])}";
   }
 
   String visitAdd(HAdd node) => visitInvokeStatic(node);
@@ skipping 226 matching lines @@
       default: unreachable();
     }
     return "TypeGuard: ${temporaryId(node.inputs[0])} is $type";
   }
 
   String visitIs(HIs node) {
     String type = node.typeName.toString();
     return "TypeTest: ${temporaryId(node.expression)} is $type";
   }
 }