dart2js cps: Change how type variables are accessed in constructors.

pkg/compiler/lib/src/closure.dart

Index: pkg/compiler/lib/src/closure.dart
diff --git a/pkg/compiler/lib/src/closure.dart b/pkg/compiler/lib/src/closure.dart
index 355e52671e11c2de4f5bae6ae9ba1b2086376126..1b59ee36689b20d639e2ea3c9478ad53e7807b94 100644
--- a/pkg/compiler/lib/src/closure.dart
+++ b/pkg/compiler/lib/src/closure.dart
@@ -741,7 +741,8 @@ class ClosureTranslator extends Visitor {
     } else {
       Element element = elements[node];
       if (element != null && element.isTypeVariable) {
-        if (outermostElement.isConstructor) {
+        if (outermostElement.isConstructor ||
+            outermostElement.isField) {
           TypeVariableElement typeVariable = element;
           useTypeVariableAsLocal(typeVariable.type);
         } else {
@@ -1081,6 +1082,17 @@ class ClosureTranslator extends Visitor {
     inTryStatement = oldInTryStatement;
   }
 
+  visitCatchBlock(CatchBlock node) {
+    if (node.type != null) {
+      // The "on T" clause may contain type variables.
+      analyzeType(elements.getType(node.type));
+    }
+    if (node.formals != null) {
+      node.formals.visitChildren(this);
+    }
+    node.block.accept(this);
+  }
+
   visitAsyncForIn(AsyncForIn node) {
     // An `await for` loop is enclosed in an implicit try-finally.
     bool oldInTryStatement = inTryStatement;