upb:file_descriptor_parsenew_fuzzer: Use-of-uninitialized-value in resolve_fielddef

Detailed Report: https://oss-fuzz.com/testcase?key=5010696608284672 Project: upb Fuzzing Engine: libFuzzer Fuzz Target: filedescriptorparsenewfuzzer Job Type: libfuzzermsanupb Platform Id: linux Crash Type: Use-of-uninitialized-value Crash Address: Crash State: resolvefielddef upbDefPoolAddFile...