Revert instance inlining.

tests/language/instance_inline_test.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+// Test inlining of assignments in parameter passing. If [StringScanner.charAt]
+// is inlined, the argument expresion [: ++byteOffset :] should not be
+// duplicated.
+
+class StringScanner {
+  final String string;
+  int byteOffset = -1;
+
+  StringScanner(this.string);
+
+  int nextByte() => charAt(++byteOffset);
+
+  int charAt(index)
+      => (string.length > index) ? string.charCodeAt(index) : -1;
+}
+
+void main() {
+  var scanner = new StringScanner('az9');
+  Expect.equals(0x61, scanner.nextByte()); // Expect a.
+  Expect.equals(0x7A, scanner.nextByte()); // Expect z.
+  Expect.equals(0x39, scanner.nextByte()); // Expect 9.
+  Expect.equals(-1, scanner.nextByte());
+}