tests: remove last uses of C_LOCALE_OUTPUT

Remove the last uses of the C_LOCALE_OUTPUT prerequisite as well as
the prerequisite itself. This is a follow-up to d162b25f95 (tests:
remove support for GIT_TEST_GETTEXT_POISON, 2021-01-20), as well as
the preceding commit where we removed the simpler uses of
C_LOCALE_OUTPUT.

Here I'm slightly refactoring a test added in 21e5ad50fc (safecrlf:
Add mechanism to warn about irreversible crlf conversions,
2008-02-06), as well as getting rid of another "test_have_prereq
C_LOCALE_OUTPUT" use.

I'm not leaving the prerequisite itself in place for in-flight changes
as there currently are none that introduce new tests that rely on it,
and because C_LOCALE_OUTPUT is currently a noop on the master branch
we likely won't have any new submissions that use it.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t0020-crlf.sh

@@ -87,10 +87,8 @@ test_expect_success 'safecrlf: print warning only once' '
 	git commit -m "nowarn" &&
 	for w in Oh here is CRLFQ in text; do echo $w; done | q_to_cr >doublewarn &&
 	git add doublewarn 2>err &&
-	if test_have_prereq C_LOCALE_OUTPUT
-	then
-		test $(grep "CRLF will be replaced by LF" err | wc -l) = 1
-	fi
+	grep "CRLF will be replaced by LF" err >err.warnings &&
+	test_line_count = 1 err.warnings
 '
 
 

t/t9003-help-autocorrect.sh

@@ -56,11 +56,8 @@ test_expect_success 'autocorrect can be declined altogether' '
 	git config help.autocorrect never &&
 
 	test_must_fail git lfg 2>actual &&
-	if test_have_prereq C_LOCALE_OUTPUT
-	then
-		grep "is not a git command" actual &&
-		test_line_count = 1 actual
-	fi
+	grep "is not a git command" actual &&
+	test_line_count = 1 actual
 '
 
 test_done

t/test-lib.sh

@@ -1519,11 +1519,6 @@ test -n "$USE_LIBPCRE2" && test_set_prereq PCRE
 test -n "$USE_LIBPCRE2" && test_set_prereq LIBPCRE2
 test -z "$NO_GETTEXT" && test_set_prereq GETTEXT
 
-# Used to be used for GIT_TEST_GETTEXT_POISON=false. Only here as a
-# shim for other in-flight changes. Should not be used and will be
-# removed soon.
-test_set_prereq C_LOCALE_OUTPUT
-
 if test -z "$GIT_TEST_CHECK_CACHE_TREE"
 then
 	GIT_TEST_CHECK_CACHE_TREE=true