Update CFG: call receiers are evaluated before arguments

ql/src/codeql_ruby/controlflow/internal/ControlFlowGraphImpl.qll

@@ -321,9 +321,9 @@ module Trees {
   private class CallTree extends StandardPostOrderTree, Call {
     // this.getBlock() is not included as it uses a different scope
     final override AstNode getChildNode(int i) {
-      result = this.getArguments() and i = 0
+      result = this.getReceiver() and i = 0
       or
-      result = this.getReceiver() and i = 1
+      result = this.getArguments() and i = 1
       or
       result = this.getMethod() and i = 2
     }

ql/test/library-tests/controlflow/graph/Cfg.expected

@@ -646,7 +646,7 @@ cfg.rb:
 #-----|  -> Break
 
 #   35| If
-#-----|  -> 42
+#-----|  -> self
 
 #   35| false
 #-----| false -> If
@@ -655,13 +655,13 @@ cfg.rb:
 #-----|  -> Case
 
 #   39| self
-#-----|  -> puts
+#-----|  -> 42
 
 #   39| puts
 #-----|  -> Call
 
 #   39| 42
-#-----|  -> self
+#-----|  -> puts
 
 #   41| Case
 #-----|  -> 10