Update corelib/ and lib/ to use the new try-catch syntax.

lib/compiler/implementation/tree/nodes.dart

Index: lib/compiler/implementation/tree/nodes.dart
diff --git a/lib/compiler/implementation/tree/nodes.dart b/lib/compiler/implementation/tree/nodes.dart
index 6ecdebe622b2bd8cea38be343d9fbb471a5e9eb9..c535d9a697bd9042dc5204530859e1056432fdc8 100644
--- a/lib/compiler/implementation/tree/nodes.dart
+++ b/lib/compiler/implementation/tree/nodes.dart
@@ -114,7 +114,7 @@ class Node implements Hashable {
     Unparser unparser = new Unparser();
     try {
       return unparser.unparse(this);
-    } catch (var e, var trace) {
+    } catch (e, trace) {
       print(trace);
       return '<<unparse error: ${getObjectDescription()}: ${unparser.sb}>>';
     }
@@ -665,7 +665,7 @@ class LiteralInt extends Literal<int> {
       Token valueToken = token;
       if (valueToken.kind === PLUS_TOKEN) valueToken = valueToken.next;
       return parseInt(valueToken.value.slowToString());
-    } catch (FormatException ex) {
+    } on FormatException catch (ex) {
       (this.handler)(token, ex);
     }
   }
@@ -684,7 +684,7 @@ class LiteralDouble extends Literal<double> {
       Token valueToken = token;
       if (valueToken.kind === PLUS_TOKEN) valueToken = valueToken.next;
       return parseDouble(valueToken.value.slowToString());
-    } catch (FormatException ex) {
+    } on FormatException catch (ex) {
       (this.handler)(token, ex);
     }
   }