Merge branch 'nk/diff-files-vs-fsmonitor'

"git diff" and other commands that share the same machinery to compare with working tree files have been taught to take advantage of the fsmonitor data when available. * nk/diff-files-vs-fsmonitor: p7519-fsmonitor: add a git add benchmark p7519-fsmonitor: refactor to avoid code duplication perf lint: add make test-lint to perf tests t/perf: add fsmonitor perf test for git diff t/perf/p7519-fsmonitor.sh: warm cache on first git status t/perf/README: elaborate on output format fsmonitor: use fsmonitor data in `git diff`