Let breakpad build with -Wall on OS X and Linux.

src/client/mac/handler/dynamic_images.cc

 // Copyright (c) 2007, Google Inc.
 // 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
@@ skipping 346 matching lines @@
                                            cpu_type);
 
   if(invalidEntriesCount != 0) {
     return 0;
   }
 
   assert(list.n_value);
   return list.n_value;
 }
 
-#if TARGET_OS_IPHONE
+#if TARGET_OS_IPHONE || MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_6
 static bool HasTaskDyldInfo() {
   return true;
 }
 #else
 static SInt32 GetOSVersionInternal() {
   SInt32 os_version = 0;
   Gestalt(gestaltSystemVersion, &os_version);
   return os_version;
 }
 
 static SInt32 GetOSVersion() {
   static SInt32 os_version = GetOSVersionInternal();
   return os_version;
 }
 
 static bool HasTaskDyldInfo() {
-#if MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_6
-  return true;
-#else
   return GetOSVersion() >= 0x1060;
-#endif
 }
-#endif  // TARGET_OS_IPHONE
+#endif  // TARGET_OS_IPHONE || MAC_OS_X_VERSION_MIN_REQUIRED >= 10_6
 
 uint64_t DynamicImages::GetDyldAllImageInfosPointer() {
   if (HasTaskDyldInfo()) {
     task_dyld_info_data_t task_dyld_info;
     mach_msg_type_number_t count = TASK_DYLD_INFO_COUNT;
     if (task_info(task_, TASK_DYLD_INFO, (task_info_t)&task_dyld_info,
                   &count) != KERN_SUCCESS) {
       return 0;
     }
 
@@ skipping 167 matching lines @@
     cpu_type_t cpu_type;
     size_t cpuTypeSize = sizeof(cpu_type);
     sysctl(mib, static_cast<u_int>(mibLen), &cpu_type, &cpuTypeSize, 0, 0);
     return cpu_type;
   }
 
   return GetNativeCPUType();
 }
 
 }  // namespace google_breakpad