INT 21 - LANtastic - GET SHARED DIRECTORY INFORMATION
        AX = 5FB1h
        DS:SI -> 64-byte buffer for link description
        ES:DI -> ASCIZ machine and shared directory name in form
                 "\\machine\shared-resource"
Return: CF clear if successful
            CX = access control list privileges for requesting user (see below)
        CF set on error
            AX = error code

Bitfields for access control list:
 bit 4  (I) allow expansion of indirect files
 bit 5  (A) allow attribute changing
 bit 6  (P) allow physical access to device
 bit 7  (E) allow program execution
 bit 8  (N) allow file renaming
 bit 9  (K) allow directory deletion
 bit 10 (D) allow file deletion
 bit 11 (L) allow file/directory lookups
 bit 12 (M) allow directory creation
 bit 13 (C) allow file creation
 bit 14 (W) allow open for write and writing
 bit 15 (R) allow open for read and reading

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