C#: Extract compound operator assignments as is.

Author: michaelnebel

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

@@ -23,15 +23,12 @@ public static Assignment Create(ExpressionNodeInfo info)
         protected override void PopulateExpression(TextWriter trapFile)
         {
             var operatorKind = OperatorKind;
+            // TODO: THIS CHECK CAN BE SIMPLIFIED - As we now always consider this to be an operator invocation.
             if (operatorKind.HasValue)
             {
-                // Convert assignment such as `a += b` into `a = a + b`.
-                var simpleAssignExpr = new Expression(new ExpressionInfo(Context, Type, Location, ExprKind.SIMPLE_ASSIGN, this, 2, isCompilerGenerated: true, null));
-                Create(Context, Syntax.Left, simpleAssignExpr, 1);
-                var opexpr = new Expression(new ExpressionInfo(Context, Type, Location, operatorKind.Value, simpleAssignExpr, 0, isCompilerGenerated: true, null));
-                Create(Context, Syntax.Left, opexpr, 0, isCompilerGenerated: true);
-                Create(Context, Syntax.Right, opexpr, 1);
-                opexpr.OperatorCall(trapFile, Syntax);
+                Create(Context, Syntax.Left, this, 0);
+                Create(Context, Syntax.Right, this, 1);
+                OperatorCall(trapFile, Syntax);
             }
             else
             {