Clean up GIT_UNUSED macros on all platforms

It turns out that commit 31e9cfc4cbcaf1b38cdd3dbe3282a8f57e5366a5
did not fix the GIT_USUSED behavior on all platforms.  This commit
walks through and really cleans things up more thoroughly, getting
rid of the unnecessary stuff.

To remove the use of some GIT_UNUSED, I ended up adding a couple
of new iterators for hashtables that allow you to iterator just
over keys or just over values.

In making this change, I found a bug in the clar tests (where we
were doing *count++ but meant to do (*count)++ to increment the
value).  I fixed that but then found the test failing because it
was not really using an empty repo.  So, I took some of the code
that I wrote for iterator testing and moved it to clar_helpers.c,
then made use of that to make it easier to open fixtures on a
per test basis even within a single test file.

1 files changed, 4 insertions, 4 deletions

diff --git a/tests-clar/attr/repo.c b/tests-clar/attr/repo.c
index 9f6a49bf4..2afea23d6 100644
--- a/tests-clar/attr/repo.c
+++ b/tests-clar/attr/repo.c
@@ -104,12 +104,12 @@ void test_attr_repo__get_many(void)
 }
 
 static int count_attrs(
-	const char *GIT_UNUSED(name),
-	const char *GIT_UNUSED(value),
+	const char *name,
+	const char *value,
 	void *payload)
 {
-	GIT_UNUSED_ARG(name);
-	GIT_UNUSED_ARG(value);
+	GIT_UNUSED(name);
+	GIT_UNUSED(value);
 
 	*((int *)payload) += 1;