illumos gate

Build errors with gcc 10:

    ../../common/io/comstar/stmf/lun_map.c: In function 'stmf_session_prepare_report_lun_data':
    ../../common/io/comstar/stmf/lun_map.c:279:10: error: array subscript 9 is above array bounds of '
    uint8_t[4]' {aka 'unsigned char[4]'} [-Werror=array-bounds]
      279 |   xd->buf[8 + (ent << 3) + 1] = (uchar_t)i;
          |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~
    In file included from ../../common/io/comstar/stmf/lun_map.c:41:
    ../../common/io/comstar/stmf/stmf_impl.h:423:11: note: while referencing 'buf'
      423 |  uint8_t  buf[4];
          |           ^~~
    ../../common/io/comstar/stmf/lun_map.c:280:10: error: array subscript 8 is above array bounds of '
    uint8_t[4]' {aka 'unsigned char[4]'} [-Werror=array-bounds]
      280 |   xd->buf[8 + (ent << 3) + 0] = ((uchar_t)(i >> 8));
          |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~
    In file included from ../../common/io/comstar/stmf/lun_map.c:41:
    ../../common/io/comstar/stmf/stmf_impl.h:423:11: note: while referencing 'buf'
      423 |  uint8_t  buf[4];
          |           ^~~
    cc1: all warnings being treated as errors
    *** Error code 1
    dmake: Warning: Command failed for target `obj64/lun_map.o'
    Current working directory /code/illumos-gate/usr/src/uts/intel/stmf

The problem is about the structure field uint8_t buf⁴, which is used as if uint8_t buf[]. The compiler knows the allocation size and does warn about going past array end. The right approach would be to use flexible array there, but at this point I do not know why the size 4 was used there.