Update almost all tests (except co19) to use the new try-catch syntax.

tests/language/named_parameters3_test.dart

Index: tests/language/named_parameters3_test.dart
diff --git a/tests/language/named_parameters3_test.dart b/tests/language/named_parameters3_test.dart
index 65b56f09a47bf9d672f49776313f980e0159f076..c5376bd6e6ab452c4ef17efb7b62cddac008d574 100644
--- a/tests/language/named_parameters3_test.dart
+++ b/tests/language/named_parameters3_test.dart
@@ -12,7 +12,7 @@ main() {
   bool foundError = false;
   try {
     test(10, x:99);  // 1 positional arg, as expected. Param x does not exist.
-  } catch (Exception e) {
+  } on Exception catch (e) {
     foundError = true;
   }
   Expect.equals(true, foundError);