Fix ARM build for gcc-4.6.

src/arm/lithium-gap-resolver-arm.cc

Index: src/arm/lithium-gap-resolver-arm.cc
===================================================================
--- src/arm/lithium-gap-resolver-arm.cc	(revision 8995)
+++ src/arm/lithium-gap-resolver-arm.cc	(working copy)
@@ -254,7 +254,6 @@
     } else {
       ASSERT(destination->IsStackSlot());
       ASSERT(!in_cycle_);  // Constant moves happen after all cycles are gone.
-      MemOperand destination_operand = cgen_->ToMemOperand(destination);
       __ mov(kSavedValueRegister, source_operand);
       __ str(kSavedValueRegister, cgen_->ToMemOperand(destination));
     }
@@ -265,8 +264,7 @@
       __ vmov(cgen_->ToDoubleRegister(destination), source_register);
     } else {
       ASSERT(destination->IsDoubleStackSlot());
-      MemOperand destination_operand = cgen_->ToMemOperand(destination);
-      __ vstr(source_register, destination_operand);
+      __ vstr(source_register, cgen_->ToMemOperand(destination));
     }
 
   } else if (source->IsDoubleStackSlot()) {