dart2js: Pass type information to constructor rather than add later.

pkg/compiler/lib/src/js_emitter/program_builder/program_builder.dart

Index: pkg/compiler/lib/src/js_emitter/program_builder/program_builder.dart
diff --git a/pkg/compiler/lib/src/js_emitter/program_builder/program_builder.dart b/pkg/compiler/lib/src/js_emitter/program_builder/program_builder.dart
index efec052e37bd4eba4be5b2e4340d662a0334e658..b819b179f1abca479031df1111fa0c84298ec361 100644
--- a/pkg/compiler/lib/src/js_emitter/program_builder/program_builder.dart
+++ b/pkg/compiler/lib/src/js_emitter/program_builder/program_builder.dart
@@ -499,12 +499,14 @@ class ProgramBuilder {
     return new Class(
         element, name, null, [], instanceFields, [], [], [], [], [], [], null,
         isDirectlyInstantiated: true,
+        hasRtiField: true, // TODO(sra): Incrementally track this need.

[Siggi Cherem (dart-lang), 2016/09/07 17:49:38]

I'm OK keeping this as true - but would it be correct to use
backend.classNeedsRtiField(element) here too?

[sra1, 2016/09/07 18:16:06]

I'll change it although this method is unused.

         onlyForRti: false,
         isNative: backend.isNative(element));
   }
 
   Class _buildClass(ClassElement element) {
     bool onlyForRti = collector.classesOnlyNeededForRti.contains(element);
+    bool hasRtiField = backend.classNeedsRtiField(element);
     if (backend.isJsInterop(element)) {
       // TODO(jacobr): check whether the class has any active static fields
       // if it does not we can suppress it completely.
@@ -635,6 +637,7 @@ class ProgramBuilder {
           isChecks,
           typeTests.functionTypeIndex,
           isDirectlyInstantiated: isInstantiated,
+          hasRtiField: hasRtiField,
           onlyForRti: onlyForRti);
     } else {
       result = new Class(
@@ -651,6 +654,7 @@ class ProgramBuilder {
           isChecks,
           typeTests.functionTypeIndex,
           isDirectlyInstantiated: isInstantiated,
+          hasRtiField: hasRtiField,
           onlyForRti: onlyForRti,
           isNative: backend.isNative(element));
     }