Commit: Add support for displaying and merging GNU_BUILD_NOTEs

[Nick Clifton]

Hi H.J.

> NT_GNU_PROPERTY_TYPE_0 isn't dumped properly:
> 
> https://sourceware.org/bugzilla/show_bug.cgi?id=21231
> 
> This patch fixes it.   OK for master?

Approved - please apply.

Cheers
  Nick