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

Source/platform/heap/AddressSanitizer.h

Index: Source/platform/heap/AddressSanitizer.h
diff --git a/Source/platform/heap/AddressSanitizer.h b/Source/platform/heap/AddressSanitizer.h
index 88477f61c1c4992774b706e4a83d6cababd9b9cd..528f0055f86cb01ba11c025d76efbdad9d135479 100644
--- a/Source/platform/heap/AddressSanitizer.h
+++ b/Source/platform/heap/AddressSanitizer.h
@@ -54,8 +54,16 @@
 // 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;