Update clar and recreate cl_assert_equal_sz

This updates clar to the version without cl_assert_equal_sz and
then adds a new version of that macro the clar_libgit2.h.  The new
version works around a strange issue that seemed to be arising on
release builds with VS 10 64-bit builds.

tests-clar/clar.h

@@ -68,7 +68,6 @@ void cl_fixture_cleanup(const char *fixture_name);
 
 #define cl_assert_equal_p(p1,p2) clar__assert_equal(__FILE__,__LINE__,"Pointer mismatch: " #p1 " != " #p2, 1, "%p", (p1), (p2))
 
-#define cl_assert_equal_sz(sz1,sz2) clar__assert_equal(__FILE__,__LINE__,#sz1 " != " #sz2, 1, "%"PRIuZ, (size_t)(sz1), (size_t)(sz2))
 
 void clar__fail(
 	const char *file,

tests-clar/clar_libgit2.h

@@ -43,6 +43,11 @@ GIT_INLINE(void) clar__assert_in_range(
 	}
 }
 
+#define cl_assert_equal_sz(sz1,sz2) do { \
+	size_t __sz1 = (sz1), __sz2 = (sz2); \
+	clar__assert_equal(__FILE__,__LINE__,#sz1 " != " #sz2, 1, "%"PRIuZ, __sz1, __sz2); \
+} while (0)
+
 #define cl_assert_in_range(L,V,H) \
 	clar__assert_in_range((L),(V),(H),__FILE__,__LINE__,"Range check: " #V " in [" #L "," #H "]", 1)