[lsan] handle 'new T[0]' where T is a type with DTOR; fixes https://code.google.com/p/address-sanitizer/issues/detail?id=257

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@198932 91177308-0d34-0410-b5e6-96231b3b80d8