Use inlined double temporary object for unary operation, add tests. Fix disassembler crash.

tests/standalone/src/DoubleTempTest.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 correct usage of inlined double temporary objects.
+
+main() {
+  for (int i = 0; i < 2000; i++) {
+    testBinaryOp();
+    testUnaryOp();
+  }
+}
+
+
+// VM: temporary double should not be used as result of division,
+// otherwise the function always returns the same object.
+double divide(double a, double b) {
+  return a / b;
+}
+
+testBinaryOp() {
+  var x = divide(1.0, 2.0);
+  var y = divide(2.0, 3.0);
+  Expect.notEquals(x, y);
+}
+
+
+// VM: temporary double should be used only for "-b", otherwise the
+// function would always return the same object.
+double unary(double a, double b) {
+  return -(a * (-b));
+}
+
+
+testUnaryOp() {
+  var x = unary(1.0, 2.0);
+  var y = unary(3.0, 4.0);
+  Expect.equals(2.0, x);
+}