Fix build on OpenBSD/i386.

src/atomicops.h

 // 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 51 matching lines @@
 // MacOS is an exception to the implicit conversion rule above,
 // because it uses long for intptr_t.
 typedef int64_t Atomic64;
 #else
 typedef intptr_t Atomic64;
 #endif
 #endif
 
 // Use AtomicWord for a machine-sized pointer.  It will use the Atomic32 or
 // Atomic64 routines below, depending on your architecture.
+#if defined(__OpenBSD__) && defined(__i386__)
+typedef Atomic32 AtomicWord;
+#else
 typedef intptr_t AtomicWord;
+#endif
 
 // Atomically execute:
 //      result = *ptr;
 //      if (*ptr == old_value)
 //        *ptr = new_value;
 //      return result;
 //
 // I.e., replace "*ptr" with "new_value" if "*ptr" used to be "old_value".
 // Always return the old value of "*ptr"
 //
@@ skipping 75 matching lines @@
 #include "atomicops_internals_x86_gcc.h"
 #elif defined(__GNUC__) && defined(V8_HOST_ARCH_ARM)
 #include "atomicops_internals_arm_gcc.h"
 #elif defined(__GNUC__) && defined(V8_HOST_ARCH_MIPS)
 #include "atomicops_internals_mips_gcc.h"
 #else
 #error "Atomic operations are not supported on your platform"
 #endif
 
 #endif  // V8_ATOMICOPS_H_