Use new ASAN APIs for scanning ASAN fake stacks during garbage collection.

Source/heap/AddressSanitizer.h

Index: Source/heap/AddressSanitizer.h
diff --git a/Source/heap/AddressSanitizer.h b/Source/heap/AddressSanitizer.h
index 2104217426f27bec0a2d67de870fcff81bc476b6..2908ea7aa2f171587e86843736bb39cc7b9e51ef 100644
--- a/Source/heap/AddressSanitizer.h
+++ b/Source/heap/AddressSanitizer.h
@@ -35,32 +35,8 @@
 // Windows).
 // FIXME: Add Windows support here.
 #if defined(ADDRESS_SANITIZER) && !OS(WIN)

[kcc1, 2014/02/06 13:44:06]

remember that this part depends on 
https://code.google.com/p/chromium/issues/detail?id=340196
https://code.google.com/p/chromium/issues/detail?id=341352

[Mads Ager (chromium), 2014/02/06 14:15:17]

Yes, I will. I'll land the change to use this header separately as soon as I
can. Then I will land this change on top when all the compilers have been
updated to the version containing the new APIs.

-extern "C" {
-    // Marks memory region [addr, addr+size) as unaddressable.
-    // This memory must be previously allocated by the user program. Accessing
-    // addresses in this region from instrumented code is forbidden until
-    // this region is unpoisoned. This function is not guaranteed to poison
-    // the whole region - it may poison only subregion of [addr, addr+size) due
-    // to ASan alignment restrictions.
-    // Method is NOT thread-safe in the sense that no two threads can
-    // (un)poison memory in the same memory region simultaneously.
-    void __asan_poison_memory_region(void const volatile*, size_t);
-    // Marks memory region [addr, addr+size) as addressable.
-    // This memory must be previously allocated by the user program. Accessing
-    // addresses in this region is allowed until this region is poisoned again.
-    // This function may unpoison a superregion of [addr, addr+size) due to
-    // ASan alignment restrictions.
-    // Method is NOT thread-safe in the sense that no two threads can
-    // (un)poison memory in the same memory region simultaneously.
-    void __asan_unpoison_memory_region(void const volatile*, size_t);
-
-    // User code should use macros instead of functions.
-#define ASAN_POISON_MEMORY_REGION(addr, size)   \
-    __asan_poison_memory_region((addr), (size))
-#define ASAN_UNPOISON_MEMORY_REGION(addr, size) \
-    __asan_unpoison_memory_region((addr), (size))
+#include <sanitizer/asan_interface.h>
 #define NO_SANITIZE_ADDRESS __attribute__((no_sanitize_address))
-}
 #else
 #define ASAN_POISON_MEMORY_REGION(addr, size)   \
     ((void)(addr), (void)(size))