dart2js cps_ir: Use interceptors for is-checks (version 2)

pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart

Index: pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
index 3fd8503e585d248dbc1a834d7ac3356571fde2c8..5a30fc1a6684227d7c18ae7052e713c522b18755 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
@@ -243,7 +243,15 @@ class SExpressionStringifier extends Indentation implements Visitor<String> {
   String visitTypeTest(TypeTest node) {
     String value = access(node.value);
     String typeArguments = node.typeArguments.map(access).join(' ');
-    return '(TypeTest $value ${node.dartType} ($typeArguments))';
+    String interceptor = node.interceptor == null

[Kevin Millikin (Google), 2015/10/07 14:10:49]

We've sort of given up on parsing the S-expressions for now, but for the future,
we should probably make the optional part surrounded by parentheses and always
there:

String interceptor = node.interceptor == null
    ? ''
    : access(node.interceptor);

and with " ($interceptor)" in the returned string below.

[sra1, 2015/10/07 17:45:58]

Done.

+        ? ''
+        : ' ${access(node.interceptor)}';
+    return '(TypeTest $value ${node.dartType} ($typeArguments)$interceptor)';
+  }
+
+  String visitTypeTestViaFlag(TypeTestViaFlag node) {
+    String interceptor = access(node.interceptor);
+    return '(TypeTestViaFlag $interceptor ${node.dartType})';
   }
 
   String visitLiteralList(LiteralList node) {