Follow-up fix to my change to IsPowerOfTwo: Alignment of one means no alignment, not zero.

runtime/vm/assembler_mips.cc

 // Copyright (c) 2013, 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.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/longjump.h"
 #include "vm/runtime_entry.h"
@@ skipping 812 matching lines @@
   // Adjust SP for PC, RA, FP, PP pushed in EnterDartFrame, and return.
   Ret();
   delay_slot()->addiu(SP, SP, Immediate(4 * kWordSize));
 }
 
 
 void Assembler::ReserveAlignedFrameSpace(intptr_t frame_space) {
   // Reserve space for arguments and align frame before entering
   // the C++ world.
   AddImmediate(SP, -frame_space);
-  if (OS::ActivationFrameAlignment() > 0) {
+  if (OS::ActivationFrameAlignment() > 1) {
     LoadImmediate(TMP1, ~(OS::ActivationFrameAlignment() - 1));
     and_(SP, SP, TMP1);
   }
 }
 
 
 void Assembler::EnterCallRuntimeFrame(intptr_t frame_space) {
   const intptr_t kPushedRegistersSize =
       kDartVolatileCpuRegCount * kWordSize +
       2 * kWordSize +  // FP and RA.
@@ skipping 134 matching lines @@
     Bind(&msg);
     break_(Instr::kMsgMessageCode);
   }
 #endif
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS