add template for directives

fuzz/corpus/hashicorp%terraforminternal%terraform%testdata%plan-count-var%main.tf

@@ -0,0 +1,10 @@
+variable "instance_count" {}
+
+resource "aws_instance" "foo" {
+  count = var.instance_count
+  foo   = "foo"
+}
+
+resource "aws_instance" "bar" {
+  foo = join(",", aws_instance.foo.*.foo)
+}