INT 31 P - DPMI 1.0+ - ALLOCATE SHARED MEMORY
        AX = 0D00h
        ES:(E)DI -> shared memory allocation request structure (see below)
Return: CF clear if successful
            request structure updated
        CF set on error
            AX = error code (8012h,8013h,8014h,8016h,8021h) (see AX=0000h)
Note:   first 16 bytes of memory block will be initialized to zeros on the
          first allocation
SeeAlso: AX=0501h,AX=0D01h,AX=0D02h

Format of shared memory allocation request structure:
Offset  Size    Description
 00h    DWORD   requested length of shared memory block in bytes
 04h    DWORD   (return) allocated length of block
 08h    DWORD   (return) shared memory handle
 0Ch    DWORD   (return) linear address of memory block
 10h    PWORD   selector:offset32 of ASCIZ name for memory block
                (name max 128 bytes)
 16h  2 BYTEs   reserved
 18h  4 BYTEs   reserved (00h)

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