Hello,

I've tried to run a R7RS program and ran into an error with the
`error-object-irritants` procedure. According to R7RS-small, it returns
a list of irritants for the error object, but under Guile it returns #f
instead of an empty list. This behavior deviates from other R7RS
implementations I've tested the program against.

I've attached both a reproduction script (invoke with `guile -q --r7rs
-s test.scm`) and a patch that resolves the issue.

Guile version: 3.0.9
Machine type: x86_64-pc-linux-gnu
Operating system: Arch Linux
OS package version: `pacman -Q guile`: guile 3.0.9-1