[PATCH] libdw: Handle DWARF5 DW_FORM_implicit_const. Add dwarf_getabbrevattr_data.

[Mark Wielaard]

On Fri, 2018-02-09 at 18:25 +0100, Mark Wielaard wrote:
> Handle the new DW_FORM_implicit_const. The value of this form is embedded
> in the abbrev data (as sleb128) and not in the info DIE data. This also
> adds a new function dwarf_getabbrevattr_data which allows getting any
> data/value associated with a form. eu-readelf will use this new function
> to show the DW_FORM_implicit_const value.

Pushed to master.