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, 3 insertions, 3 deletions

diff --git a/tests-clar/core/dirent.c b/tests-clar/core/dirent.c
index 78237096..9c366bf9 100644
--- a/tests-clar/core/dirent.c
+++ b/tests-clar/core/dirent.c
@@ -88,10 +88,10 @@ static int one_entry(void *state, git_buf *path)
 	return GIT_ERROR;
 }
 
-static int dont_call_me(void *GIT_UNUSED(state), git_buf *GIT_UNUSED(path))
+static int dont_call_me(void *state, git_buf *path)
 {
-	GIT_UNUSED_ARG(state);
-	GIT_UNUSED_ARG(path);
+	GIT_UNUSED(state);
+	GIT_UNUSED(path);
 	return GIT_ERROR;
 }