Dataflow: Add totalorder predicates to all languages.

go/ql/lib/semmle/go/dataflow/internal/DataFlowPrivate.qll

@@ -310,6 +310,16 @@ class DataFlowCallable extends TDataFlowCallable {
     this.asSummarizedCallable()
         .hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
   }
+
+  /** Gets a best-effort total ordering. */
+  int totalorder() {
+    this =
+      rank[result](DataFlowCallable c, string file, int startline, int startcolumn |
+        c.hasLocationInfo(file, startline, startcolumn, _, _)
+      |
+        c order by file, startline, startcolumn
+      )
+  }
 }
 
 /** A function call relevant for data flow. */
@@ -333,6 +343,16 @@ class DataFlowCall extends Expr {
     or
     not exists(this.getEnclosingFunction()) and result.asFileScope() = this.getFile()
   }
+
+  /** Gets a best-effort total ordering. */
+  int totalorder() {
+    this =
+      rank[result](DataFlowCall c, int startline, int startcolumn |
+        c.getLocation().hasLocationInfo(_, startline, startcolumn, _, _)
+      |
+        c order by startline, startcolumn
+      )
+  }
 }
 
 /** Holds if `e` is an expression that always has the same Boolean value `val`. */