Fix LoadFieldByIndex to take mutable heap-numbers into account.

src/ia32/lithium-codegen-ia32.h

Index: src/ia32/lithium-codegen-ia32.h
diff --git a/src/ia32/lithium-codegen-ia32.h b/src/ia32/lithium-codegen-ia32.h
index 079595cba58dcebb2e91aab1cc6dd357c6f4e2b6..b29f0f1a0f6b98678755b19eac2aa970ed4017d4 100644
--- a/src/ia32/lithium-codegen-ia32.h
+++ b/src/ia32/lithium-codegen-ia32.h
@@ -163,6 +163,9 @@ class LCodeGen: public LCodeGenBase {
   void DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
                                        Label* map_check);
   void DoDeferredInstanceMigration(LCheckMaps* instr, Register object);
+  void DoDeferredLoadMutableDouble(LLoadFieldByIndex* instr,
+                                   Register object,
+                                   Register index);
 
   // Parallel move support.
   void DoParallelMove(LParallelMove* move);