Ruby: Add an extra barrier guard test

Author: hmac

ruby/ql/test/library-tests/dataflow/barrier-guards/barrier-guards.expected

@@ -5,4 +5,4 @@
 | barrier-guards.rb:27:8:27:19 | ... != ... | barrier-guards.rb:28:5:28:7 | foo | barrier-guards.rb:27:8:27:10 | foo | false |
 | barrier-guards.rb:37:4:37:20 | call to include? | barrier-guards.rb:38:5:38:7 | foo | barrier-guards.rb:37:17:37:19 | foo | true |
 | barrier-guards.rb:43:4:43:15 | ... == ... | barrier-guards.rb:45:9:45:11 | foo | barrier-guards.rb:43:4:43:6 | foo | true |
-| barrier-guards.rb:69:4:69:21 | call to include? | barrier-guards.rb:70:5:70:7 | foo | barrier-guards.rb:69:18:69:20 | foo | true |
+| barrier-guards.rb:70:4:70:21 | call to include? | barrier-guards.rb:71:5:71:7 | foo | barrier-guards.rb:70:18:70:20 | foo | true |

ruby/ql/test/library-tests/dataflow/barrier-guards/barrier-guards.rb

@@ -63,11 +63,30 @@
     my_lambda()
 end
 
+foos = nil
 foos = ["foo"]
-bars = ["bar"]
+bars = NotAnArray.new
 
 if foos.include?(foo)
     foo
 else
     foo
-end
+end
+
+if bars.include?(foo)
+    foo
+else
+    foo
+end
+
+bars = ["bar"]
+
+if condition
+    bars = nil
+end
+
+if bars.include?(foo)
+    foo
+else
+    foo
+end