Code quality improvements

Author: tamasvajk

csharp/extractor/Semmle.Extraction.CSharp/Entities/Assembly.cs

@@ -5,8 +5,6 @@ namespace Semmle.Extraction.CSharp.Entities
 {
     internal class Assembly : Location
     {
-        public override Context Context => (Context)base.Context;
-
         private readonly string assemblyPath;
         private readonly IAssemblySymbol assembly;
         private readonly bool isOutputAssembly;

csharp/extractor/Semmle.Extraction.CSharp/Entities/Base/Entity.cs

@@ -6,7 +6,7 @@ namespace Semmle.Extraction.CSharp
 {
     public abstract class Entity : IEntity
     {
-        public virtual Context Context { get; }
+        public Context Context { get; }
 
         protected Entity(Context context)
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Locations/File.cs

@@ -11,7 +11,6 @@ public class File : CachedEntity<string>
         protected readonly string originalPath;
         private readonly Lazy<PathTransformer.ITransformedPath> transformedPathLazy;
         protected PathTransformer.ITransformedPath TransformedPath => transformedPathLazy.Value;
-        public override Context Context => (Context)base.Context;
         public override Microsoft.CodeAnalysis.Location? ReportingLocation => null;
 
         public override bool NeedsPopulation => true;

csharp/extractor/Semmle.Extraction.CSharp/Entities/Locations/NonGeneratedSourceLocation.cs

@@ -5,8 +5,6 @@ namespace Semmle.Extraction.CSharp.Entities
 {
     internal class NonGeneratedSourceLocation : SourceLocation
     {
-        public override Context Context => (Context)base.Context;
-
         protected NonGeneratedSourceLocation(Context cx, Microsoft.CodeAnalysis.Location init)
             : base(cx, init)
         {