C++: Remove getLocationImpl predicate that is always overridden

Also remove the predicate referred to in ints implementation, as it is no
longer used.

Author: jketema

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowPrivate.qll

@@ -56,19 +56,11 @@ class Node0Impl extends TIRDataFlowNode0 {
   /** Gets the operands corresponding to this node, if any. */
   Operand asOperand() { result = this.(OperandNode0).getOperand() }
 
-  /** INTERNAL: Do not use. */
-  Location getLocationImpl() {
-    none() // overridden by subclasses
-  }
-
   /** INTERNAL: Do not use. */
   string toStringImpl() {
     none() // overridden by subclasses
   }
 
-  /** Gets the location of this node. */
-  final Location getLocation() { result = this.getLocationImpl() }
-
   /** Gets a textual representation of this node. */
   final string toString() { result = this.toStringImpl() }
 
@@ -113,8 +105,6 @@ abstract class InstructionNode0 extends Node0Impl {
 
   override DataFlowType getType() { result = getInstructionType(instr, _) }
 
-  final override Location getLocationImpl() { result = instr.getLocation() }
-
   override string toStringImpl() {
     // This predicate is overridden in subclasses. This default implementation
     // does not use `Instruction.toString` because that's expensive to compute.
@@ -158,8 +148,6 @@ abstract class OperandNode0 extends Node0Impl {
 
   override DataFlowType getType() { result = getOperandType(op, _) }
 
-  final override Location getLocationImpl() { result = op.getLocation() }
-
   override string toStringImpl() { result = op.toString() }
 
   final override predicate isGLValue() { exists(getOperandType(op, true)) }

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowUtil.qll

@@ -390,8 +390,6 @@ private class Node0 extends Node, TNode0 {
 
   override DataFlowType getType() { result = node.getType() }
 
-  override Location getLocationImpl() { result = node.getLocationImpl() }
-
   override string toStringImpl() {
     // This predicate is overridden in subclasses. This default implementation
     // does not use `Instruction.toString` because that's expensive to compute.