Speed up "make test" and related cleanups

Signed-off-by: Clifford Wolf <clifford@clifford.at>

tests/various/run-test.sh

@@ -1,12 +1,20 @@
 #!/usr/bin/env bash
 set -e
+{
+echo "all::"
 for x in *.ys; do
-	echo "Running $x.."
-	../../yosys -ql ${x%.ys}.log $x
+	echo "all:: run-$x"
+	echo "run-$x:"
+	echo "	@echo 'Running $x..'"
+	echo "	@../../yosys -ql ${x%.ys}.log $x"
 done
 for s in *.sh; do
 	if [ "$s" != "run-test.sh" ]; then
-		echo "Running $s.."
-		bash $s
+		echo "all:: run-$s"
+		echo "run-$s:"
+		echo "	@echo 'Running $s..'"
+		echo "	@bash $s"
 	fi
 done
+} > run-test.mk
+exec ${MAKE:-make} -f run-test.mk