Ruby: fix regression for methods in singleton classes

Author: asgerf

ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowDispatch.qll

@@ -413,10 +413,10 @@ private module Cached {
           //   end
           // end
           // ```
-          exists(Module target |
+          exists(Module target, MethodBase caller |
             target = m.getSuperClass*() and
-            selfInMethod(sourceNode.(SsaSelfDefinitionNode).getVariable(), any(SingletonMethod sm),
-              target) and
+            selfInMethod(sourceNode.(SsaSelfDefinitionNode).getVariable(), caller, target) and
+            singletonMethod(caller, _, _) and
             // Singleton methods declared in a block in the top-level may spuriously end up being seen as singleton
             // methods on Object, if the block is actually evaluated in the context of another class.
             // The 'self' inside such a singleton method could then be any class, leading to self-calls

ruby/ql/test/library-tests/modules/callgraph.expected

@@ -265,6 +265,8 @@ getTarget
 | private.rb:104:1:104:20 | call to new | calls.rb:117:5:117:16 | new |
 | private.rb:104:1:104:28 | call to call_m1 | private.rb:91:3:93:5 | call_m1 |
 | private.rb:105:1:105:20 | call to new | calls.rb:117:5:117:16 | new |
+| toplevel_self_singleton.rb:29:13:29:19 | call to call_me | toplevel_self_singleton.rb:25:9:26:11 | call_me |
+| toplevel_self_singleton.rb:30:13:30:20 | call to call_you | toplevel_self_singleton.rb:28:9:31:11 | call_you |
 unresolvedCall
 | calls.rb:23:9:23:19 | call to singleton_m |
 | calls.rb:26:9:26:18 | call to instance_m |
@@ -356,8 +358,6 @@ unresolvedCall
 | toplevel_self_singleton.rb:13:9:13:27 | call to ab_singleton_method |
 | toplevel_self_singleton.rb:17:12:21:1 | call to new |
 | toplevel_self_singleton.rb:19:9:19:27 | call to ab_singleton_method |
-| toplevel_self_singleton.rb:29:13:29:19 | call to call_me |
-| toplevel_self_singleton.rb:30:13:30:20 | call to call_you |
 privateMethod
 | calls.rb:1:1:3:3 | foo |
 | calls.rb:39:1:41:3 | call_instance_m |