Makefile, .gitignore, tests/cc-compat.sh: brought up-to-date

tests/cc-compat.sh

@@ -1,40 +0,0 @@
-#!/bin/sh
-
-# Copyright (c) 2023–2024 Emma Tebibyte <emma@tebibyte.media>
-# SPDX-License-Identifier: FSFAP
-#
-# Copying and distribution of this file, with or without modification, are
-# permitted in any medium without royalty provided the copyright notice and this
-# notice are preserved.  This file is offered as-is, without any warranty.
-
-set -e
-
-if ! ls Makefile >/dev/null 2>&1
-then
-	printf '%s: Run this script in the root of the project.\n' "$0" 1>&2 
-	exit 64 # sysexits.h(3) EX_USAGE
-fi
-
-make clean
-./configure clean
-./configure
-
-for CC in cc \
-	clang \
-	gcc \
-	'zig cc'
-do
-	export CC
-
-	command -v "$(printf '%s\n' "$CC" | cut -d ' ' -f1)" >/dev/null 2>&1 \
-		|| continue
-
-	printf '%s: %s: Testing build.\n' "$0" "$CC"
-
-	make CC="$CC" && printf '%s: Build successful.\n' "$0"
-
-	ls -lA build/bin
-
-	make clean
-	printf '\n'
-done