[patch] More DWARF-4 support

[Tom Tromey]

>>>>> "Cary" == Cary Coutant <ccoutant@google.com> writes:

Cary> 	(DW_AT_main_subprogram, DW_AT_data_bit_offset, DW_AT_const_expr,
Cary> 	DW_AT_enum_class, DW_AT_linkage_name, DW_AT_GNU_guarded_by,
Cary> 	DW_AT_GNU_pt_guarded_by, DW_AT_GNU_guarded, DW_AT_GNU_pt_guarded,
Cary> 	DW_AT_GNU_locks_excluded, DW_AT_GNU_exclusive_locks_required,
Cary> 	DW_AT_GNU_shared_locks_required, DW_AT_GNU_odr_signature): New
Cary> 	attributes.

Where are these GNU extensions documented?

I think dwarf2.h should refer to the documentation for all extensions.
Undocumented extensions have already caused problems for people writing
new readers.

Tom