C#: Cleanup the extractor code.

Author: michaelnebel

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Invocation.cs

@@ -26,15 +26,12 @@ private Invocation(ExpressionNodeInfo info)
 
         private bool IsOperatorCall() => Kind == ExprKind.OPERATOR_INVOCATION;
 
-        private bool IsAccessorInvocation() => Kind == ExprKind.ACCESSOR_INVOCATION;
-
         private bool IsValidMemberAccessKind()
         {
             return Kind == ExprKind.METHOD_INVOCATION ||
                 IsEventDelegateCall() ||
                 IsExplicitDelegateInvokeCall() ||
-                IsOperatorCall() ||
-                IsAccessorInvocation();
+                IsOperatorCall();
         }
 
         protected override void PopulateExpression(TextWriter trapFile)
@@ -133,14 +130,6 @@ private static bool IsOperatorLikeCall(ExpressionNodeInfo info)
                 original!.MethodKind == MethodKind.UserDefinedOperator;
         }
 
-        private static bool IsAccessorLikeInvocation(ExpressionNodeInfo info)
-        {
-            return info.SymbolInfo.Symbol is IMethodSymbol method &&
-                method.TryGetExtensionMethod(out var original) &&
-                (original!.MethodKind == MethodKind.PropertyGet ||
-                 original!.MethodKind == MethodKind.PropertySet);
-        }
-
         public IMethodSymbol? TargetSymbol
         {
             get
@@ -252,10 +241,6 @@ private static ExprKind GetKind(ExpressionNodeInfo info)
             {
                 return ExprKind.OPERATOR_INVOCATION;
             }
-            if (IsAccessorLikeInvocation(info))
-            {
-                return ExprKind.ACCESSOR_INVOCATION;
-            }
             return ExprKind.METHOD_INVOCATION;
         }
 

csharp/extractor/Semmle.Extraction.CSharp/Kinds/ExprKind.cs

@@ -133,7 +133,6 @@ public enum ExprKind
         COLLECTION = 136,
         SPREAD_ELEMENT = 137,
         INTERPOLATED_STRING_INSERT = 138,
-        ACCESSOR_INVOCATION = 139,
         DEFINE_SYMBOL = 999,
     }
 }