Fix a perfrormance degradation in Mandelbrot: double comparison may have

runtime/vm/opt_code_generator_ia32.cc

Index: runtime/vm/opt_code_generator_ia32.cc
===================================================================
--- runtime/vm/opt_code_generator_ia32.cc	(revision 3639)
+++ runtime/vm/opt_code_generator_ia32.cc	(working copy)
@@ -2277,6 +2277,8 @@
   const Bool& bool_false = Bool::ZoneHandle(Bool::False());
   CodeGenInfo left_info(node->left());
   CodeGenInfo right_info(node->right());
+  left_info.set_allow_temp(true);
+  right_info.set_allow_temp(true);
   VisitLoadTwo(node->left(), node->right(), EAX, EDX);
   DeoptimizationBlob* deopt_blob = NULL;
   if (!left_info.IsClass(double_class_) || !right_info.IsClass(double_class_)) {
@@ -2370,7 +2372,7 @@
     }
     // Fall through if condition is not supported.
   } else if (AtIdNodeHasClassAt(node, node->id(), double_class_, 0)) {
-    // Double comparison
+    // Double comparison.
     if (GenerateDoubleComparison(node)) {
       return;
     }