Move symbol demangling to dart:_internal to remove dart:core dependency on dart:mirrors.

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 962a1c73abfdd70dbd29af3592ca855605d5f0a2..e80dd47d94a74c06ff5b99d19f23e861e9463418 100644
--- a/runtime/lib/mirrors_patch.dart
+++ b/runtime/lib/mirrors_patch.dart
@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import "dart:_internal" as _symbol_dev;
+import "dart:_internal" as internal;
 
 /**
  * Returns a [MirrorSystem] for the current isolate.
@@ -51,42 +51,7 @@ patch class MirrorSystem {
   }
 
   /* patch */ static String getName(Symbol symbol) {
-    String string = _symbol_dev.Symbol.getName(symbol);
-
-    // 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 = true;
-      }
-    }
-    // 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();
+    return internal.Symbol.getUnmangledName(symbol);
   }
 
   /* patch */ static Symbol getSymbol(String name, [LibraryMirror library]) {
@@ -95,7 +60,7 @@ patch class MirrorSystem {
       throw new ArgumentError(library);
     }
     if (library != null) name = _mangleName(name, library._reflectee);
-    return new _symbol_dev.Symbol.unvalidated(name);
+    return new internal.Symbol.unvalidated(name);
   }
 
   static _mangleName(String name, _MirrorReference lib)