Use new try-catch syntax in runtime/, tools/, and utils/.

utils/pub/version.dart

Index: utils/pub/version.dart
diff --git a/utils/pub/version.dart b/utils/pub/version.dart
index 4a37062e618201a4a24a4bbd05a36c9bcc19c8b0..33a8c05c628c4c1bafb8cd308f2b36402ccebf33 100644
--- a/utils/pub/version.dart
+++ b/utils/pub/version.dart
@@ -69,7 +69,7 @@ class Version implements Comparable, Hashable, VersionConstraint {
       String build = match[8];
 
       return new Version(major, minor, patch, preRelease, build);
-    } catch (FormatException ex) {
+    } on FormatException catch (ex) {
       throw new FormatException('Could not parse "$text".');
     }
   }
@@ -183,7 +183,7 @@ class Version implements Comparable, Hashable, VersionConstraint {
     return text.split('.').map((part) {
       try {
         return parseInt(part);
-      } catch (FormatException ex) {
+      } on FormatException catch (ex) {
         // Not a number.
         return part;
       }