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

runtime/lib/symbol_patch.dart

Index: runtime/lib/symbol_patch.dart
diff --git a/runtime/lib/symbol_patch.dart b/runtime/lib/symbol_patch.dart
index 35a0d88e95bb2b470eb52e111b4ca80643ff281e..16a3ebbe0b83840b60da81f736e9fed47985cc8f 100644
--- a/runtime/lib/symbol_patch.dart
+++ b/runtime/lib/symbol_patch.dart
@@ -2,11 +2,48 @@
 // 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:mirrors';
-
 patch class Symbol {
   /* patch */ const Symbol(String name)
       : this._name = name;
 
-  /* patch */ toString() => 'Symbol("${MirrorSystem.getName(this)}")';
+  /* patch */ toString() => 'Symbol("${getUnmangledName(this)}")';
+
+  static getUnmangledName(Symbol symbol) {
+    String string = 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();
+  }
 }