Fix FreeList::zapFreedMemory to fail "use-of-uninitialized-value" on MSAN

Source/wtf/AddressSanitizer.h

Index: Source/wtf/AddressSanitizer.h
diff --git a/Source/wtf/AddressSanitizer.h b/Source/wtf/AddressSanitizer.h
index bd333708278af859bfb221b16771889faa107a9e..69ce58ce0a2ad7ae407aac9118a59ab085d63a76 100644
--- a/Source/wtf/AddressSanitizer.h
+++ b/Source/wtf/AddressSanitizer.h
@@ -22,6 +22,10 @@
 #define __lsan_unregister_root_region(addr, size) ((void)(addr), (void)(size))
 #endif
 
+#if defined(MEMORY_SANITIZER)
+#include <sanitizer/msan_interface.h>
+#endif
+
 // TODO(sof): 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
@@ -38,4 +42,10 @@
 #define NO_LAZY_SWEEP_SANITIZE_ADDRESS
 #endif
 
+#if defined(MEMORY_SANITIZER) && (!OS(WIN) || COMPILER(CLANG))
+#define NO_SANITIZE_MEMORY __attribute__((no_sanitize_memory))
+#else
+#define NO_SANITIZE_MEMORY
+#endif
+
 #endif // WTF_AddressSanitizer_h