[bug#43976] [PATCH] Chicken build system + some example eggs

[raingloom]

Here it is, chicken-build-system.

# What works
Building eggs, dependencies, importing them from search path.

# What's broken
Cross-compilation has not been attempted beacuse the Go build system I
based this on does not support it either.

# Necessary improvements
The Go build system removes some references. I was not sure if this is
needed for Chicken, so for now I left it out.

# Eggs
Some were selected because I'll need for the 9p egg, the rest because
the agrep egg was the first one I found that had dependencies, so it
was selected as a perfect test case.
I don't know if all eggs will work. Eggs that bind to native libraries
(like SDL) still need to be tested.

## SRFI-14 licensing
SRFI-14 has a weird license. The metadata says it's "BSD" but it's
clearly not BSD. I'm not sure what it is or if it's compatible with
Guix. If not, we could probably contact the authors and ask them to
relicense it.

# Chicken 4
Not attempted. Nix supports it but it's old and looks mostly abandoned.
I think we can skip it.

0001-gnu-Added-search-paths-for-Chicken-Scheme.patch
Description: Text Data

0002-guix-Added-chicken-build-system.patch
Description: Text Data

0003-gnu-Use-qualified-license-names-in-chicken.scm-inste.patch
Description: Text Data

0004-gnu-Added-imports-for-chicken-eggs.patch
Description: Text Data

0005-gnu-Added-chicken-srfi-1.patch
Description: Text Data

0006-gnu-Added-chicken-srfi-69.patch
Description: Text Data

0007-gnu-Added-chicken-iset.patch
Description: Text Data

0008-gnu-Added-chicken-datatype.patch
Description: Text Data

0009-gnu-Added-chicken-srfi-14.patch
Description: Text Data

0010-gnu-Added-chicken-agrep.patch
Description: Text Data

0011-gnu-Added-myself-to-chicken.scm-copyright.patch
Description: Text Data