kernel/slab: Simplify arguments of create_object_cache().

* alignment, cookie, constructor, destructor are rarely used
   (in fact constructors/destructors are never used at present.)

 * Add flags argument, this is more commonly used.

This allows a lot of the invocations of create_object_cache_etc
to be changed to invocations of just create_object_cache, simplifying
the code significantly.

headers/private/kernel/slab/Slab.h

@@ -43,8 +43,7 @@ extern "C" {
 #endif
 
 object_cache* create_object_cache(const char* name, size_t objectSize,
-	size_t alignment, void* cookie, object_cache_constructor constructor,
-	object_cache_destructor destructor);
+	uint32 flags);
 object_cache* create_object_cache_etc(const char* name, size_t objectSize,
 	size_t alignment, size_t maxByteUsage, size_t magazineCapacity,
 	size_t maxMagazineCount, uint32 flags, void* cookie,