Ensure constructorName symbols include private manglings.

runtime/lib/mirrors_patch.dart

Index: runtime/lib/mirrors_patch.dart
diff --git a/runtime/lib/mirrors_patch.dart b/runtime/lib/mirrors_patch.dart
index 200b1b0b1a606fa874ec579951b85dc492318274..06eb5585a1462aec1945e47311b4d8dd5e72bca1 100644
--- a/runtime/lib/mirrors_patch.dart
+++ b/runtime/lib/mirrors_patch.dart
@@ -40,20 +40,52 @@ patch TypeMirror reflectType(Type key) {
 patch class MirrorSystem {
   /* patch */ static String getName(Symbol symbol) {
     String string = _symbol_dev.Symbol.getName(symbol);
-    if (string.contains(' with ')) return string;
-    return _unmangleName(string);
+
+    // get:foo -> foo
+    // set:foo -> foo=
+    // get:_foo@xxx -> _foo
+    // set:_foo@xxx -> _foo=
+    // Class._constructor@xxx -> Class._constructor
+    // _Class@xxx._constructor@xxx -> _Class._constructor
+    // lib._S@xxx with lib._M1@xxx, lib._M2@xxx -> lib._S with lib._M1, lib._M2
+    StringBuffer result = new StringBuffer();
+    bool add_setter_suffix = false;
+    var pos = 0;
+    if (string.length >= 4 && string[3] == ':') {
+      // Drop 'get:' or 'set:' prefix.
+      pos = 4;
+      if (string[0] == 's') {
+        add_setter_suffix;
+      }
+    }
+    // Skip everything between AT and PERIOD, SPACE, COMMA or END
+    bool skip = false;
+    for (; pos < string.length; pos++) {
+      var char = string[pos];
+      if (char == '@') {
+        skip = true;
+      } else if (char == '.' || char == ' ' || char == ',') {
+        skip = false;
+      }
+      if (!skip) {
+        result.write(char);
+      }
+    }
+    if (add_setter_suffix) {
+      result.write('=');
+    }
+    return result.toString();
   }
+
   /* patch */ static Symbol getSymbol(String name, [LibraryMirror library]) {
     if (library is! LibraryMirror ||
-        ((name[0] == '_') && (library == null))) {
+        ((name.length > 0) && (name[0] == '_') && (library == null))) {
       throw new ArgumentError(library);
     }
     if (library != null) name = _mangleName(name, library._reflectee);
     return new _symbol_dev.Symbol.unvalidated(name);
   }
 
-  static _unmangleName(String name)
-      native "Mirrors_unmangleName";
   static _mangleName(String name, _MirrorReference lib)
       native "Mirrors_mangleName";
 }