gendwarfksyms: Expand type modifiers and typedefs

gendwarfksyms: Expand type modifiers and typedefs

Add support for expanding DWARF type modifiers, such as pointers,
const values etc., and typedefs. These types all have DW_AT_type
attribute pointing to the underlying type, and thus produce similar
output.

Also add linebreaks and indentation to debugging output to make it
more readable.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>