PHHIVE Hive,
      PCM_KEY_INDEX Index,
      PUNICODE_STRING SearchName,
      PHCELL_INDEX Child

Routine Description:

    Find a named key in a leaf index, if it exists. The supplied index
    may be either a fast index or a slow one.


    Hive - pointer to hive control structure for hive of interest

    Index - pointer to leaf block

    SearchName - pointer to name of key of interest

    Child - pointer to variable to receive hcell_index of found key
            HCELL_NIL if none found

Return Value:

    Index in List of last cell.  If Child != HCELL_NIL, is offset in
    list at which Child was found.  Else, is offset of last place
    we looked.

    INVALID_INDEX - resources problem; couldn't map view