OSV-2021-577 Segv on unknown address in dwg_free_MTEXTATTRIBUTEOBJECTCONTEXTDATA_private

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32604 Crash type: Segv on unknown address Crash state: dwgfreeMTEXTATTRIBUTEOBJECTCONTEXTDATAprivate dwgfreeMTEXTATTRIBUTEOBJECTCONTEXTDATA dwgfreevariablenoclass...