chore(users): grfn -> aspen

Change-Id: I6c6847fac56f0a9a1a2209792e00a3aec5e672b9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10809
Autosubmit: aspen <root@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: lukegb <lukegb@tvl.fyi>

users/aspen/achilles/ach/Makefile

@@ -0,0 +1,15 @@
+default: simple
+
+%.ll: %.ach
+	cargo run -- compile $< -o $@ -f llvm
+
+%.o: %.ll
+	llc $< -o $@ -filetype=obj
+
+%: %.o
+	clang $< -o $@
+
+.PHONY: clean
+
+clean:
+	@rm -f *.ll *.o simple functions