Remove semaphore alignment check for posix platform.

BUG=chromium:605349
LOG=NO

Review-Url: https://codereview.chromium.org/2304203002
Cr-Commit-Position: refs/heads/master@{#39157}

src/base/platform/semaphore.cc

@@ -73,19 +73,6 @@ bool Semaphore::WaitFor(const TimeDelta& rel_time) {
 #elif V8_OS_POSIX
 
 Semaphore::Semaphore(int count) {
-  // The sem_init() does not check for alignment of the native handle.
-  // Unaligned native handle can later cause a failure in semaphore signal.
-  // Check the alignment here to catch the failure earlier.
-  // Context: crbug.com/605349.
-#if V8_OS_AIX || V8_OS_FREEBSD
-  // On aix sem_t is of type int. On FreeBSD, it's a struct of 32 bits fields.
-  const uintptr_t kSemaphoreAlignmentMask = sizeof(int) - 1;
-#else
-  const uintptr_t kSemaphoreAlignmentMask = sizeof(void*) - 1;
-#endif
-  CHECK_EQ(
-      0, reinterpret_cast<uintptr_t>(&native_handle_) &
-      kSemaphoreAlignmentMask);
   DCHECK(count >= 0);
   int result = sem_init(&native_handle_, 0, count);
   DCHECK_EQ(0, result);