C++: Fix up IR data flow QLDoc

Author: jbj

cpp/ql/src/semmle/code/cpp/ir/dataflow/DataFlow.qll

@@ -13,8 +13,10 @@
  *
  * To use global (interprocedural) data flow, extend the class
  * `DataFlow::Configuration` as documented on that class. To use local
- * (intraprocedural) data flow, invoke `DataFlow::localFlow` or
- * `DataFlow::LocalFlowStep` with arguments of type `DataFlow::Node`.
+ * (intraprocedural) data flow between expressions, call
+ * `DataFlow::localExprFlow`. For more general cases of local data flow, call
+ * `DataFlow::localFlow` or `DataFlow::localFlowStep` with arguments of type
+ * `DataFlow::Node`.
  */
 
 import cpp

cpp/ql/src/semmle/code/cpp/ir/dataflow/DataFlow2.qll

@@ -6,7 +6,7 @@
  * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
  * `DataFlow4::Configuration`.
  *
- * See `semmle.code.cpp.dataflow.DataFlow` for the full documentation.
+ * See `semmle.code.cpp.ir.dataflow.DataFlow` for the full documentation.
  */
 
 import cpp

cpp/ql/src/semmle/code/cpp/ir/dataflow/DataFlow3.qll

@@ -6,7 +6,7 @@
  * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
  * `DataFlow4::Configuration`.
  *
- * See `semmle.code.cpp.dataflow.DataFlow` for the full documentation.
+ * See `semmle.code.cpp.ir.dataflow.DataFlow` for the full documentation.
  */
 
 import cpp

cpp/ql/src/semmle/code/cpp/ir/dataflow/DataFlow4.qll

@@ -6,7 +6,7 @@
  * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
  * `DataFlow4::Configuration`.
  *
- * See `semmle.code.cpp.dataflow.DataFlow` for the full documentation.
+ * See `semmle.code.cpp.ir.dataflow.DataFlow` for the full documentation.
  */
 
 import cpp