Improve List implementation.

dart/frog/leg/ssa/codegen.dart

Index: dart/frog/leg/ssa/codegen.dart
diff --git a/dart/frog/leg/ssa/codegen.dart b/dart/frog/leg/ssa/codegen.dart
index 222ced5db3b35fc15fb38744d745150a70897a4d..9898eedbea91b91dc9da966a5020f7f769987656 100644
--- a/dart/frog/leg/ssa/codegen.dart
+++ b/dart/frog/leg/ssa/codegen.dart
@@ -633,7 +633,8 @@ class SsaCodeGenerator implements HVisitor {
     use(node.index);
     buffer.add(' >= ');
     use(node.length);
-    buffer.add(") throw 'Out of bounds'");
+    buffer.add(") ");
+    generateFail('ioore', node.index);
   }
 
   visitIntegerCheck(HIntegerCheck node) {
@@ -641,7 +642,17 @@ class SsaCodeGenerator implements HVisitor {
     use(node.value);
     buffer.add(' !== (');
     use(node.value);
-    buffer.add(" | 0)) throw 'Illegal argument'");
+    buffer.add(" | 0)) ");
+    generateFail('iae', node.value);
+  }
+
+  void generateFail(String helperName, HInstruction argument) {
+    Element helper = compiler.findHelper(new SourceString(helperName));
+    compiler.registerStaticUse(helper);
+    buffer.add(compiler.namer.isolateAccess(helper));
+    buffer.add("(");
+    use(argument);
+    buffer.add(")");
   }
 
   void addIndentation() {