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

Merge commit '1b593e1ea4' as 'third_party/git'
2020-01-11 23:36:56 +00:00 · 2020-01-11 23:36:56 +00:00 · 7ef0d62730
commit 7ef0d62730
parent 6a2a300707 1b593e1ea4
3629 changed files with 1139935 additions and 0 deletions
--- a/third_party/git/t/t4101/diff.1-0
+++ b/third_party/git/t/t4101/diff.1-0
@ -0,0 +1,6 @@
+--- a/frotz
+++ b/frotz
+@@ -1,3 +1,2 @@
+ a
+ b
+-c