C#: Use Gvn comparison instead of StructuralComparisonConfiguration in Constants.

Author: michaelnebel

csharp/ql/lib/semmle/code/csharp/commons/Constants.qll

@@ -105,31 +105,12 @@ private module ConstantComparisonOperation {
   }
 }
 
-private class StructuralComparisonConfig extends StructuralComparison::StructuralComparisonConfiguration {
-  StructuralComparisonConfig() { this = "CompareIdenticalValues" }
-
-  override predicate candidate(ControlFlowElement x, ControlFlowElement y) {
-    exists(ComparisonTest ct |
-      x = ct.getFirstArgument() and
-      y = ct.getSecondArgument()
-    )
-  }
-
-  ComparisonTest getComparisonTest() {
-    exists(Element x, Element y |
-      result.getFirstArgument() = x and
-      result.getSecondArgument() = y and
-      same(x, y)
-    )
-  }
-}
-
 /**
  * Holds if comparison test `ct` compares two structurally identical
  * expressions.
  */
 predicate comparesIdenticalValues(ComparisonTest ct) {
-  ct = any(StructuralComparisonConfig c).getComparisonTest()
+  StructuralComparison::sameGvn(ct.getFirstArgument(), ct.getSecondArgument())
 }
 
 /**