Don't use ".catch" in dart2js generated code.

pkg/js_ast/lib/src/printer.dart

Index: pkg/js_ast/lib/src/printer.dart
diff --git a/pkg/js_ast/lib/src/printer.dart b/pkg/js_ast/lib/src/printer.dart
index b2fd29d3058d42536ae480494f789bfd0c841736..d5c1d9b57048ed6397487f0fff16830e6733f7eb 100644
--- a/pkg/js_ast/lib/src/printer.dart
+++ b/pkg/js_ast/lib/src/printer.dart
@@ -920,6 +920,7 @@ class Printer implements NodeVisitor {
     // reserved word.  We don't generate fields with reserved word names except
     // for 'super'.
     if (field == '"super"') return false;
+    if (field == '"catch"') return false;
     return true;
   }