validation/prototype: regression for skipping prototypes

Signed-off-by: Azat Khuzhin <a3at.mail@gmail.com>
Signed-off-by: Christopher Li <sparse@chrisli.org>
diff --git a/validation/prototype.c b/validation/prototype.c
new file mode 100644
index 0000000..481cc93
--- /dev/null
+++ b/validation/prototype.c
@@ -0,0 +1,6 @@
+static int prototype(void);
+
+/*
+ * check-name: Compile skip function prototype
+ * check-command: ./sparsec -c $file -o tmp.o
+ */