Various ASan exemptions to allow Oilpan pre-sweep poisoning of unmarkeds.

Source/platform/heap/AddressSanitizer.h

 /*
  * Copyright (C) 2014 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 36 matching lines @@
 #define __lsan_register_root_region(addr, size) ((void)(addr), (void)(size))
 #define __lsan_unregister_root_region(addr, size) ((void)(addr), (void)(size))
 #endif
 
 // FIXME: Have to handle (ADDRESS_SANITIZER && _WIN32) differently as it uses
 // both Clang (which supports the __attribute__ syntax) and CL (which doesn't)
 // as long as we use "clang-cl /fallback". This shouldn't be needed when Clang
 // handles all the code without falling back to CL.
 #if defined(ADDRESS_SANITIZER) && (!OS(WIN) || COMPILER(CLANG))
 #define NO_SANITIZE_ADDRESS __attribute__((no_sanitize_address))
+#if ENABLE(OILPAN)
+// TODO(Oilpan): a temporary annotation while lazy sweeping is phased in.
+// Remove the ENABLE(OILPAN) condition when lazy sweeping is globally enabled.
+#define NO_LAZY_SWEEP_SANITIZE_ADDRESS NO_SANITIZE_ADDRESS

[Nico, 2016/10/02 00:54:39]

Now that oilpan is on, do we still need this alternative spelling of
NO_SANITIZE_ADDRESS?

+#else
+#define NO_LAZY_SWEEP_SANITIZE_ADDRESS
+#endif
 #else
 #define NO_SANITIZE_ADDRESS
+#define NO_LAZY_SWEEP_SANITIZE_ADDRESS
 #endif
 
 const size_t asanMagic = 0xabefeed0;
 const size_t asanDeferMemoryReuseCount = 2;
 const size_t asanDeferMemoryReuseMask = 0x3;
 
 #endif