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

tests/language/call_nonexistent_constructor_test.dart

Index: tests/language/call_nonexistent_constructor_test.dart
diff --git a/tests/language/call_nonexistent_constructor_test.dart b/tests/language/call_nonexistent_constructor_test.dart
index d85b726c6a1ba825af6d45ced31820b17e21ad78..a50548d720d3194d66f18fec9971362d3696df90 100644
--- a/tests/language/call_nonexistent_constructor_test.dart
+++ b/tests/language/call_nonexistent_constructor_test.dart
@@ -19,13 +19,13 @@ main() {
   new A.foo(42);
   try {
     new A.bar(foo());
-  } catch (String e) {
+  } on String catch (e) {
     i = 1;
   }
   Expect.equals(1, i);
   try {
     new A();
-  } catch (NoSuchMethodException e) {
+  } on NoSuchMethodException catch (e) {
     i = 2;
   }
   Expect.equals(2, i);