maint: Remove unnecessary standard library extern function decls.

[Collin Funk]

Hi Simon,

Are you okay with me pushing the following two patches?

Patch 0001 removes most (all?) of the extern function decls that
should be in the standard library. They seems harmless, but maybe they
can mess with Gnulib declarations. We should probably just rely on
those anyways.

Patch 0002 removes the use of the 'register' keyword. NetBSD did this
20 years ago [1][2]. I assume the other BSDs did too, but NetBSD seems
closer to what we have. So this frivolous change should actually make
it easier to diff. :)

Also, I remembered to run 'make indent && make syntax-check' this time...

[1] 
https://github.com/NetBSD/src/commit/797d779cf1e0fea886f40c274a5e87d72e1d4b77
[2] 
https://github.com/NetBSD/src/commit/b87e54c002f7345d281ff7ab0c325d0336a8a8a2

Collin

0001-maint-Remove-unnecessary-standard-library-extern-fun.patch
Description: Text Data

0002-maint-Remove-uses-of-the-register-keyword.patch
Description: Text Data