autofdo doesnt compile.

[3/17] Building CXX object CMakeFiles/perfdata_reader.dir/perfdata_reader.cc.o
FAILED: CMakeFiles/perfdata_reader.dir/perfdata_reader.cc.o
/usr/bin/c++ -DHAVE_LLVM=1 -DLLVM_GETELFFILE_RET_REFERENCE=1 -DLLVM_VERSION_MAJOR=14 -DLLVM_VERSION_MINOR=0 -I/usr/lib/llvm-14/include -I../ -I../third_party/glog/src -I../third_party/abseil -I../third_party/perf_data_converter/src -I../third_party/perf_data_converter/src/quipper -I. -Ithird_party/glog -I../third_party/googletest/googletest/include -I../third_party/googletest/googlemock/include -I../util/regexp -O3 -DNDEBUG -std=gnu++17 -MD -MT CMakeFiles/perfdata_reader.dir/perfdata_reader.cc.o -MF CMakeFiles/perfdata_reader.dir/perfdata_reader.cc.o.d -o CMakeFiles/perfdata_reader.dir/perfdata_reader.cc.o -c ../perfdata_reader.cc
../perfdata_reader.cc: In function ‘llvm::Optional > > devtools_crosstool_autofdo::FindFileNameInPerfDataWithFileBuildId(const string&, const quipper::PerfReader&, devtools_crosstool_autofdo::BinaryPerfInfo*)’:
../perfdata_reader.cc:268:17: error: could not convert ‘std::nullopt’ from ‘const std::nullopt_t’ to ‘llvm::Optional > >’
268 | return std::nullopt;
| ^~~~~~~
| |

Reproduce the CMake build using the command shown and inspect perfdata_reader.cc around line 268, including the function's llvm::Optional return type. Confirm the failure with the LLVM 14 toolchain; done means the perfdata_reader target compiles successfully without the reported conversion error.

Written by the indexing model from the issue text.