merge(third_party/git): Merge squashed git subtree at v2.23.0

Merge commit '1b593e1ea4' as 'third_party/git'

third_party/git/.gitignore

@@ -0,0 +1,240 @@
+/fuzz-commit-graph
+/fuzz_corpora
+/fuzz-pack-headers
+/fuzz-pack-idx
+/GIT-BUILD-OPTIONS
+/GIT-CFLAGS
+/GIT-LDFLAGS
+/GIT-PREFIX
+/GIT-PERL-DEFINES
+/GIT-PERL-HEADER
+/GIT-PYTHON-VARS
+/GIT-SCRIPT-DEFINES
+/GIT-USER-AGENT
+/GIT-VERSION-FILE
+/bin-wrappers/
+/git
+/git-add
+/git-add--interactive
+/git-am
+/git-annotate
+/git-apply
+/git-archimport
+/git-archive
+/git-bisect
+/git-bisect--helper
+/git-blame
+/git-branch
+/git-bundle
+/git-cat-file
+/git-check-attr
+/git-check-ignore
+/git-check-mailmap
+/git-check-ref-format
+/git-checkout
+/git-checkout-index
+/git-cherry
+/git-cherry-pick
+/git-clean
+/git-clone
+/git-column
+/git-commit
+/git-commit-graph
+/git-commit-tree
+/git-config
+/git-count-objects
+/git-credential
+/git-credential-cache
+/git-credential-cache--daemon
+/git-credential-store
+/git-cvsexportcommit
+/git-cvsimport
+/git-cvsserver
+/git-daemon
+/git-diff
+/git-diff-files
+/git-diff-index
+/git-diff-tree
+/git-difftool
+/git-difftool--helper
+/git-describe
+/git-env--helper
+/git-fast-export
+/git-fast-import
+/git-fetch
+/git-fetch-pack
+/git-filter-branch
+/git-fmt-merge-msg
+/git-for-each-ref
+/git-format-patch
+/git-fsck
+/git-fsck-objects
+/git-gc
+/git-get-tar-commit-id
+/git-grep
+/git-hash-object
+/git-help
+/git-http-backend
+/git-http-fetch
+/git-http-push
+/git-imap-send
+/git-index-pack
+/git-init
+/git-init-db
+/git-interpret-trailers
+/git-instaweb
+/git-legacy-stash
+/git-log
+/git-ls-files
+/git-ls-remote
+/git-ls-tree
+/git-mailinfo
+/git-mailsplit
+/git-merge
+/git-merge-base
+/git-merge-index
+/git-merge-file
+/git-merge-tree
+/git-merge-octopus
+/git-merge-one-file
+/git-merge-ours
+/git-merge-recursive
+/git-merge-resolve
+/git-merge-subtree
+/git-mergetool
+/git-mergetool--lib
+/git-mktag
+/git-mktree
+/git-multi-pack-index
+/git-mv
+/git-name-rev
+/git-notes
+/git-p4
+/git-pack-redundant
+/git-pack-objects
+/git-pack-refs
+/git-parse-remote
+/git-patch-id
+/git-prune
+/git-prune-packed
+/git-pull
+/git-push
+/git-quiltimport
+/git-range-diff
+/git-read-tree
+/git-rebase
+/git-rebase--preserve-merges
+/git-receive-pack
+/git-reflog
+/git-remote
+/git-remote-http
+/git-remote-https
+/git-remote-ftp
+/git-remote-ftps
+/git-remote-fd
+/git-remote-ext
+/git-remote-testpy
+/git-remote-testsvn
+/git-repack
+/git-replace
+/git-request-pull
+/git-rerere
+/git-reset
+/git-restore
+/git-rev-list
+/git-rev-parse
+/git-revert
+/git-rm
+/git-send-email
+/git-send-pack
+/git-serve
+/git-sh-i18n
+/git-sh-i18n--envsubst
+/git-sh-setup
+/git-sh-i18n
+/git-shell
+/git-shortlog
+/git-show
+/git-show-branch
+/git-show-index
+/git-show-ref
+/git-stage
+/git-stash
+/git-status
+/git-stripspace
+/git-submodule
+/git-submodule--helper
+/git-svn
+/git-switch
+/git-symbolic-ref
+/git-tag
+/git-unpack-file
+/git-unpack-objects
+/git-update-index
+/git-update-ref
+/git-update-server-info
+/git-upload-archive
+/git-upload-pack
+/git-var
+/git-verify-commit
+/git-verify-pack
+/git-verify-tag
+/git-web--browse
+/git-whatchanged
+/git-worktree
+/git-write-tree
+/git-core-*/?*
+/gitweb/GITWEB-BUILD-OPTIONS
+/gitweb/gitweb.cgi
+/gitweb/static/gitweb.js
+/gitweb/static/gitweb.min.*
+/command-list.h
+*.tar.gz
+*.dsc
+*.deb
+/git.spec
+*.exe
+*.[aos]
+*.py[co]
+.depend/
+*.gcda
+*.gcno
+*.gcov
+/coverage-untested-functions
+/cover_db/
+/cover_db_html/
+*+
+/config.mak
+/autom4te.cache
+/config.cache
+/config.log
+/config.status
+/config.mak.autogen
+/config.mak.append
+/configure
+/.vscode/
+/tags
+/TAGS
+/cscope*
+*.obj
+*.lib
+*.res
+*.sln
+*.suo
+*.ncb
+*.vcproj
+*.user
+*.idb
+*.pdb
+*.ilk
+*.iobj
+*.ipdb
+*.dll
+.vs/
+*.manifest
+Debug/
+Release/
+/UpgradeLog*.htm
+/git.VC.VC.opendb
+/git.VC.db
+*.dSYM