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

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

third_party/git/Documentation/RelNotes/1.5.3.4.txt

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+GIT v1.5.3.4 Release Notes
+==========================
+
+Fixes since v1.5.3.3
+--------------------
+
+ * Change to "git-ls-files" in v1.5.3.3 that was introduced to support
+   partial commit of removal better had a segfaulting bug, which was
+   diagnosed and fixed by Keith and Carl.
+
+ * Performance improvements for rename detection has been backported
+   from the 'master' branch.
+
+ * "git-for-each-ref --format='%(numparent)'" was not working
+   correctly at all, and --format='%(parent)' was not working for
+   merge commits.
+
+ * Sample "post-receive-hook" incorrectly sent out push
+   notification e-mails marked as "From: " the committer of the
+   commit that happened to be at the tip of the branch that was
+   pushed, not from the person who pushed.
+
+ * "git-remote" did not exit non-zero status upon error.
+
+ * "git-add -i" did not respond very well to EOF from tty nor
+   bogus input.
+
+ * "git-rebase -i" squash subcommand incorrectly made the
+   author of later commit the author of resulting commit,
+   instead of taking from the first one in the squashed series.
+
+ * "git-stash apply --index" was not documented.
+
+ * autoconfiguration learned that "ar" command is found as "gas" on
+   some systems.