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

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

third_party/git/t/t4033-diff-patience.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+test_description='patience diff algorithm'
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-diff-alternative.sh
+
+test_expect_success '--ignore-space-at-eol with a single appended character' '
+	printf "a\nb\nc\n" >pre &&
+	printf "a\nbX\nc\n" >post &&
+	test_must_fail git diff --no-index \
+		--patience --ignore-space-at-eol pre post >diff &&
+	grep "^+.*X" diff
+'
+
+test_diff_frobnitz "patience"
+
+test_diff_unique "patience"
+
+test_done