Update charted to 0.4.8 and roll

packages/petitparser/lib/src/reflection/optimize.dart

-part of petitparser.reflection;
-
-/// Returns a copy of [parser] with all settable parsers removed.
-Parser removeSettables(Parser parser) {
-  return transformParser(parser, (each) {
-    while (each is SettableParser) {
-      each = each.children.first;
-    }
-    return each;
-  });
-}
-
-/// Returns a copy of [parser] with all duplicates parsers collapsed.
-Parser removeDuplicates(Parser parser) {
-  var uniques = new Set();
-  return transformParser(parser, (source) {
-    var target = uniques.firstWhere((each) {
-      return source != each && source.isEqualTo(each);
-    }, orElse: () => null);
-    if (target == null) {
-      uniques.add(source);
-      return source;
-    } else {
-      return target;
-    }
-  });
-}