illumos gate

Issues revealed by gcc 7 build:

     ../common/elf.c: In function 'ehdr_mach_strings':
    ../common/elf.c:331:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cf[] = {
                   ^~~~~
    ../common/elf.c:336:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_nf[] = {
                   ^~~~~
    ../common/elf.c:341:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_dmp[] = {
                   ^~~~~
    ../common/elf.c: In function 'ehdr_eident_strings':
    ../common/elf.c:429:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cf[] = {
                   ^~~~~
    ../common/elf.c: In function 'ehdr_type_strings':
    ../common/elf.c:498:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cf[] = {
                   ^~~~~
    ../common/elf.c: In function 'ehdr_vers_strings':
    ../common/elf.c:560:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cf[] = {
                   ^~~~~
    ../common/elf.c: In function 'ehdr_osabi_strings':
    ../common/elf.c:808:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cf[] = {
                   ^~~~~
    ../common/elf.c:811:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_nf[] = {
                   ^~~~~
    ../common/elf.c:814:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_dmp[] = {
                   ^~~~~
    ../common/elf.c: In function 'ehdr_abivers_strings':
    ../common/elf.c:882:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cf[] = {
                   ^~~~~
    ../common/phdr.c: In function 'conv_phdr_type_strings':
    ../common/phdr.c:157:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_def[] = {
                   ^~~~~
    ./common/symbols.c: In function 'conv_sym_other_vis_strings':
    ../common/symbols.c:92:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_def[] = {
                   ^~~~~
    ../common/symbols.c:94:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cf[] = {
                   ^~~~~
    ../common/symbols.c:96:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_nf[] = {
                   ^~~~~
    ../common/symbols.c: In function 'conv_sym_info_bind_strings':
    ../common/symbols.c:243:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_def[] = {
                   ^~~~~
    ../common/symbols.c:245:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cf[] = {
                   ^~~~~
    ../common/symbols.c:247:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_nf[] = {
                   ^~~~~
    ../common/symbols.c: In function 'conv_sym_shndx_strings':
    ../common/symbols.c:344:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_def[] = {
                   ^~~~~
    ../common/symbols.c:346:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cf[] = {
                   ^~~~~
    ../common/symbols.c:348:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cfnp[] = {
                   ^~~~~
    ../common/symbols.c:350:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_nf[] = {
                   ^~~~~
    ../common/syminfo.c: In function 'conv_syminfo_boundto_strings':
    ../common/syminfo.c:170:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cf[] = {
                   ^~~~~
    ../common/syminfo.c:172:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_cfnp[] = {
                   ^~~~~
    ../common/syminfo.c:174:15: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
      static const const conv_ds_t *ds_nf[] = {
                   ^~~~~
    ../common/syms.c:3112:7: error: duplicate 'const' declaration specifier [-Werror=duplicate-decl-specifier]
     const const char *
           ^~~~~
    cc1: all warnings being treated as errors