Ruby: add test showing lack of lambda handling

Author: asgerf

ruby/ql/test/library-tests/dataflow/api-graphs/VerifyApiGraphExpectations.expected

@@ -1,2 +1,5 @@
 failures
 testFailures
+| explicit-proc.rb:2:7:2:78 | # $ reachableFromSource=Member[Foo].Method[bar].Argument[0].Parameter[0] | Missing result:reachableFromSource=Member[Foo].Method[bar].Argument[0].Parameter[0] |
+| explicit-proc.rb:6:7:6:78 | # $ reachableFromSource=Member[Foo].Method[bar].Argument[0].Parameter[0] | Missing result:reachableFromSource=Member[Foo].Method[bar].Argument[0].Parameter[0] |
+| explicit-proc.rb:10:7:10:78 | # $ reachableFromSource=Member[Foo].Method[bar].Argument[0].Parameter[0] | Missing result:reachableFromSource=Member[Foo].Method[bar].Argument[0].Parameter[0] |

ruby/ql/test/library-tests/dataflow/api-graphs/explicit-proc.rb

@@ -0,0 +1,11 @@
+Foo.bar proc { |x|
+    x # $ reachableFromSource=Member[Foo].Method[bar].Argument[0].Parameter[0]
+}
+
+Foo.bar lambda { |x|
+    x # $ reachableFromSource=Member[Foo].Method[bar].Argument[0].Parameter[0]
+}
+
+Foo.bar Proc.new { |x|
+    x # $ reachableFromSource=Member[Foo].Method[bar].Argument[0].Parameter[0]
+}