[gold] Recognize DWARF5/GCC5 DW_LANG_Fortran03 and DW_LANG_Fortran08.
DWARFv5 defines and GCC5 may output two new DW_LANG constants for the
Fortran 2003 and Fortran 2008 standards. Recognize both in gold gdb-index
as unsupported.
For consistency also add the other new DWARF5/GCC5 language constants in
the elfcpp::DW_LANG enum to match include/dwarf2.h.
elfcpp/ChangeLog:
* dwarf.h (enum DW_LANG): Add DW_LANG_C_plus_plus_11,
DW_LANG_C11, DW_LANG_C_plus_plus_14, DW_LANG_Fortran03 and
DW_LANG_Fortran08 from ../include/dwarf2.h.
gold/ChangeLog:
* gdb-index.cc (Gdb_index_info_reader::visit_top_die): Recognize
DW_LANG_Fortran03 and DW_LANG_Fortran08.