OSV-2023-1259 Use-of-uninitialized-value in std::__1::__stdoutbuf<char>::xsputn

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=64693 Crash type: Use-of-uninitialized-value Crash state: std::1::stdoutbuf::xsputn std::1::ostreambufiterator std::1::pa std::1::basicostream & std::1::putcha...