dart2js cps_ir: Use interceptors for is-checks.

pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart

Index: pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
diff --git a/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart b/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
index 01b5847cdb3073f8153280f6368fee513bed1c72..b310650a199ef9228614544c8bbeda1e72a4319d 100644
--- a/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
+++ b/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
@@ -498,6 +498,15 @@ class SubexpressionVisitor extends ExpressionVisitor<String> {
     return '$element = $value';
   }
 
+  String visitGetTypeTestProperty(GetTypeTestProperty node) {
+    String object = visitExpression(node.object);
+    if (usesInfixNotation(node.object)) {
+      object = '($object)';
+    }
+    // TODO(sra): Fix up this.
+    return '$object."is-${node.dartType}"';

[sra1, 2015/10/06 06:47:58]

How do I test this?

+  }
+
   String visitCreateBox(CreateBox node) {
     return 'CreateBox';
   }
@@ -611,4 +620,4 @@ class Names {
     }
     return name;
   }
-}
+}