Change store buffer overflow check to not rely on the store buffer being (2*Size) aligned.

src/arm/macro-assembler-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
@@ skipping 720 matching lines @@
   ExternalReference store_buffer =
       ExternalReference::store_buffer_top(isolate());
   mov(ip, Operand(store_buffer));
   ldr(scratch, MemOperand(ip));
   // Store pointer to buffer and increment buffer top.
   str(address, MemOperand(scratch, kPointerSize, PostIndex));
   // Write back new top of buffer.
   str(scratch, MemOperand(ip));
   // Call stub on end of buffer.
   // Check for end of buffer.
-  tst(scratch, Operand(StoreBuffer::kStoreBufferOverflowBit));
+  tst(scratch, Operand(StoreBuffer::kStoreBufferMask));
   if (and_then == kFallThroughAtEnd) {
-    b(eq, &done);
+    b(ne, &done);
   } else {
     DCHECK(and_then == kReturnAtEnd);
-    Ret(eq);
+    Ret(ne);
   }
   push(lr);
   StoreBufferOverflowStub store_buffer_overflow(isolate(), fp_mode);
   CallStub(&store_buffer_overflow);
   pop(lr);
   bind(&done);
   if (and_then == kReturnAtEnd) {
     Ret();
   }
 }
@@ skipping 3202 matching lines @@
     }
   }
   if (mag.shift > 0) mov(result, Operand(result, ASR, mag.shift));
   add(result, result, Operand(dividend, LSR, 31));
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM