alloc.h: move ALLOC_GROW() functions from cache.h

This allows us to replace includes of cache.h with includes of the much
smaller alloc.h in many places.  It does mean that we also need to add
includes of alloc.h in a number of C files.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ewah/bitmap.c

@@ -16,7 +16,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
-#include "cache.h"
+#include "git-compat-util.h"
+#include "alloc.h"
 #include "ewok.h"
 
 #define EWAH_MASK(x) ((eword_t)1 << (x % BITS_IN_EWORD))

ewah/ewah_bitmap.c

@@ -17,9 +17,9 @@
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 #include "git-compat-util.h"
+#include "alloc.h"
 #include "ewok.h"
 #include "ewok_rlw.h"
-#include "cache.h"
 
 static inline size_t min_size(size_t a, size_t b)
 {