Makefile, .gitignore, .editorconfig, configure, tests/cc-compat.sh: added configure script for compiler optimizations

tests/cc-compat.sh

@@ -9,18 +9,19 @@
 
 set -e
 
-if ! ls GNUmakefile >/dev/null 2>&1
+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 \
-	tcc \
 	'zig cc'
 do
 	export CC