Introduce HLocalValue and HLocalGet/Set.

lib/compiler/implementation/ssa/tracer.dart

Index: lib/compiler/implementation/ssa/tracer.dart
diff --git a/lib/compiler/implementation/ssa/tracer.dart b/lib/compiler/implementation/ssa/tracer.dart
index d8b63435755b42097cbdd40777ee511bd7a16ae6..feab15fae7eb2365b21de90414ff51c69955a25f 100644
--- a/lib/compiler/implementation/ssa/tracer.dart
+++ b/lib/compiler/implementation/ssa/tracer.dart
@@ -251,6 +251,9 @@ class HInstructionStringifier implements HVisitor<String> {
     return 'set ${temporaryId(node.receiver)} to $valueId';
   }
 
+  String visitLocalGet(HLocalGet node) => visitFieldGet(node);
+  String visitLocalSet(HLocalSet node) => visitFieldSet(node);
+
   String visitGoto(HGoto node) {
     HBasicBlock target = currentBlock.successors[0];
     return "Goto: (B${target.id})";
@@ -365,6 +368,10 @@ class HInstructionStringifier implements HVisitor<String> {
     return "p${node.sourceElement.name.slowToString()}";
   }
 
+  String visitLocalValue(HParameterValue node) {
+    return "l${node.sourceElement.name.slowToString()}";
+  }
+
   String visitPhi(HPhi phi) {
     StringBuffer buffer = new StringBuffer();
     buffer.add("Phi(");