Change 16283
Changed linux backtrace library to use backtrace() instead of libunwind.
backtrace() costs about 1 us more per call than libunwind does, but saves a dependency, so that extra 1us seems not to matter much in the face of external dependency requirements. This ensures the only external dependency is libbfd, which is more readily available on more systems than libunwind and also more likely to already be installed.
libunwind's major performance benefit over glibc is in symbolification, and we don't use libunwind for symbolification because libbfd gives us more information (i.e., filename and line numbers). So the dependency has very very little real benefit.
#review-16284
backtrace() costs about 1 us more per call than libunwind does, but saves a dependency, so that extra 1us seems not to matter much in the face of external dependency requirements. This ensures the only external dependency is libbfd, which is more readily available on more systems than libunwind and also more likely to already be installed.
libunwind's major performance benefit over glibc is in symbolification, and we don't use libunwind for symbolification because libbfd gives us more information (i.e., filename and line numbers). So the dependency has very very little real benefit.
#review-16284