Add make clean to clear the regression test results.

Author: martin

regression/Makefile

@@ -12,3 +12,10 @@ DIRS = ansi-c \
 
 test:
 	$(foreach var,$(DIRS), $(MAKE) -C $(var) test || exit 1;)
+
+clean:
+	@for dir in *; do \
+		if [ -d "$$dir" ]; then \
+			$(MAKE) -C "$$dir" clean; \
+		fi; \
+	done;