Make it easier to compile a statically linked version

It's way too big, but maybe I can try with musl or ulibc soon.

scm/inc/Makefile

@@ -4,6 +4,9 @@ run-scheme: scheme
scheme: scheme.s driver.c
	gcc -O3 -g scheme.s driver.c -o $@
scheme-static: scheme.s driver.c
	gcc -O3 -static scheme.s driver.c -o $@
asm: scheme.s
	cat scheme.s