toolchain/53363: stringlist.h symbols missing from nbcompat

[mjbauer95%gmail.com@localhost]

>Number:         53363
>Category:       toolchain
>Synopsis:       stringlist.h symbols missing from nbcompat
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    toolchain-manager
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Thu Jun 14 03:30:00 +0000 2018
>Originator:     Matthew Bauer
>Release:        7.1.2
>Organization:
N/A
>Environment:
Linux eris 4.14.44 #1-NixOS SMP Fri May 25 14:18:02 UTC 2018 x86_64 GNU/Linux
>Description:
Currently, the nbcompt found in NetBSD/src/tools/compat does not detect the symbols or headers for stringlist.h. This has become a problem for me on Linux because lots of software from NetBSD uses the stringlist.h headers but they are unavailable on both Glibc and Musl.

Other headers that it would be useful to include symbols for as well (but not nearly as important):

- nlist.h
- wchar.h

Also things like "humanize_number" and "readpassphrase" seem to be used a lot but again I don't want to prioritize it.
>How-To-Repeat:
Should be self explanatory. Here is a build log for where this coming up for me:

https://hydra.nixos.org/build/75774321
>Fix:
Adding include/stringlist.h & lib/libc/gen/stringlist.c to tools/compat + a HAVE_STRINGLIST_H define.