t/unit-tests: rename clar-based unit tests to have a common prefix

All of the code files for unit tests using the self-grown unit testing
framework have a "t-" prefix to their name. This makes it easy to
identify them and use globbing in our Makefile and in other places. On
the other hand though, our clar-based unit tests have no prefix at all
and thus cannot easily be discerned from other files in the unit test
directory.

Introduce a new "u-" prefix for clar-based unit tests. This prefix will
be used in a subsequent commit to easily identify such tests.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/unit-tests/generate-clar-decls.sh

@@ -11,6 +11,9 @@ shift
 
 for suite in "$@"
 do
-	sed -ne "s/^\(void test_$(basename "${suite%.c}")__[a-zA-Z_0-9][a-zA-Z_0-9]*(void)\)$/extern \1;/p" "$suite" ||
+	suite_name=$(basename "$suite")
+	suite_name=${suite_name%.c}
+	suite_name=${suite_name#u-}
+	sed -ne "s/^\(void test_${suite_name}__[a-zA-Z_0-9][a-zA-Z_0-9]*(void)\)$/extern \1;/p" "$suite" ||
 	exit 1
 done >"$OUTPUT"