[ubsan] Blacklist a false positive

Bug: v8:3770
Change-Id: I59d73ef672e64fd722317c84afc6bc5cb387f5b1
Reviewed-on: https://chromium-review.googlesource.com/c/1404448Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58702}

tools/ubsan/blacklist.txt

 #############################################################################
-# UBSan blacklist.
\ No newline at end of file
+# UBSan blacklist.
+
+# UBSan bug, fixed in LLVM r350779. Drop this suppression when that
+# revision has rolled into Chromium's bundled Clang.
+fun:*v8*internal*NewArray*