Implement a list tracer phase, that tries to find element types in individual lists.

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

 // Copyright (c) 2013, 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:async' show EventSink;
 
 import 'ssa.dart';
 import '../js_backend/js_backend.dart';
@@ skipping 161 matching lines @@
   final JavaScriptItemCompilationContext context;
   final HBasicBlock currentBlock;
 
   HInstructionStringifier(this.context, this.currentBlock, this.compiler);
 
   visit(HInstruction node) => node.accept(this);
 
   String temporaryId(HInstruction instruction) {
     String prefix;
     HType type = instruction.instructionType;
-    if (type.isMutableArray(compiler)) {
+    if (type.isExtendableArray(compiler)) {
+      prefix = 'e';
+    } else if (type.isFixedArray(compiler)) {
+      prefix = 'f';
+    } else if (type.isMutableArray(compiler)) {
       prefix = 'm';
     } else if (type.isReadableArray(compiler)) {
       prefix = 'a';
-    } else if (type.isExtendableArray(compiler)) {
-      prefix = 'e';
+    } else if (type.isString(compiler)) {
+      prefix = 's';
+    } else if (type.isIndexable(compiler)) {
+      prefix = 'r';
     } else if (type == HType.BOOLEAN) {
       prefix = 'b';
     } else if (type == HType.INTEGER) {
       prefix = 'i';
     } else if (type == HType.DOUBLE) {
       prefix = 'd';
     } else if (type == HType.NUMBER) {
       prefix = 'n';
-    } else if (type.isString(compiler)) {
-      prefix = 's';
     } else if (type == HType.UNKNOWN) {
       prefix = 'v';
     } else if (type == HType.CONFLICTING) {
       prefix = 'c';
-    } else if (type.isIndexable(compiler)) {
-      prefix = 'r';
     } else if (type == HType.NULL) {
       prefix = 'u';
     } else {
       prefix = 'U';
     }
     return "$prefix${instruction.id}";
   }
 
   String visitBailoutTarget(HBailoutTarget node) {
     StringBuffer envBuffer = new StringBuffer();
@@ skipping 346 matching lines @@
         ? temporaryId(node.inputs[1])
         : '';
     return "TypeConversion: ${temporaryId(node.checkedInput)} to "
       "${node.instructionType} $otherInput";
   }
 
   String visitRangeConversion(HRangeConversion node) {
     return "RangeConversion: ${node.checkedInput}";
   }
 }