Use eight level of critnibs in the tracker

Multilevel maps are needed to support the case
when one memory pool acts as a memory provider
for another memory pool (nested memory pooling).

Signed-off-by: Lukasz Dorau <[email protected]>

Author: ldorau

include/umf/base.h

@@ -47,7 +47,8 @@ typedef enum umf_result_t {
         6, ///< Failure in user provider code (i.e in user provided callback)
     UMF_RESULT_ERROR_DEPENDENCY_UNAVAILABLE =
         7, ///< External required dependency is unavailable or missing
-    UMF_RESULT_ERROR_UNKNOWN = 0x7ffffffe ///< Unknown or internal error
+    UMF_RESULT_ERROR_INTERNAL = 8,        ///< Internal error
+    UMF_RESULT_ERROR_UNKNOWN = 0x7ffffffe ///< Unknown error
 } umf_result_t;
 
 #ifdef __cplusplus