ARM: Fix GC bug with previous change...

src/arm/codegen-arm.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4384 matching lines @@
     runtime.Branch(ne);
 
       // Get the double value from the base into vfp register d0.
     __ ObjectToDoubleVFPRegister(base, d0,
                                  scratch1, scratch2, heap_number_map, s0,
                                  runtime.entry_label(),
                                  AVOID_NANS_AND_INFINITIES);
     __ vsqrt(d0, d0);
 
     __ bind(&allocate_return);
-    __ AllocateHeapNumberWithValue(
-        base, d0, scratch1, scratch2, heap_number_map, runtime.entry_label());
+    Register scratch3 = r5;
+    __ AllocateHeapNumberWithValue(scratch3, d0, scratch1, scratch2,
+                                   heap_number_map, runtime.entry_label());
+    __ mov(base, scratch3);
     done.Jump();
 
     runtime.Bind();
 
     // Push back the arguments again for the runtime call.
     frame_->EmitPush(base);
     frame_->EmitPush(exponent);
     frame_->CallRuntime(Runtime::kMath_pow, 2);
     __ Move(base, r0);
 
@@ skipping 6693 matching lines @@
   __ bind(&string_add_runtime);
   __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM