C#: Use nameof in nullability attributes

csharp/autobuilder/Semmle.Autobuild.Shared/BuildActions.cs

@@ -140,7 +140,7 @@ namespace Semmle.Autobuild.Shared
         /// <summary>
         /// Returns the file name and extension of the specified path string.
         /// </summary>
-        [return: NotNullIfNotNull("path")]
+        [return: NotNullIfNotNull(nameof(path))]
         string? GetFileName(string? path);
 
         /// <summary>

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

@@ -126,7 +126,7 @@ namespace Semmle.Extraction.CSharp.Entities
             }
         }
 
-        [return: NotNullIfNotNull("constructor")]
+        [return: NotNullIfNotNull(nameof(constructor))]
         public static new Constructor? Create(Context cx, IMethodSymbol? constructor)
         {
             if (constructor is null)

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

@@ -232,7 +232,7 @@ namespace Semmle.Extraction.CSharp.Entities
         /// <param name="cx"></param>
         /// <param name="methodDecl"></param>
         /// <returns></returns>
-        [return: NotNullIfNotNull("methodDecl")]
+        [return: NotNullIfNotNull(nameof(methodDecl))]
         public static Method? Create(Context cx, IMethodSymbol? methodDecl)
         {
             if (methodDecl is null)

csharp/extractor/Semmle.Extraction.CSharp/SymbolExtensions.cs

@@ -591,7 +591,7 @@ namespace Semmle.Extraction.CSharp
         public static INamedTypeSymbol? GetNonObjectBaseType(this ITypeSymbol symbol, Context cx) =>
             symbol is ITypeParameterSymbol || SymbolEqualityComparer.Default.Equals(symbol.BaseType, cx.Compilation.ObjectType) ? null : symbol.BaseType;
 
-        [return: NotNullIfNotNull("symbol")]
+        [return: NotNullIfNotNull(nameof(symbol))]
         public static IEntity? CreateEntity(this Context cx, ISymbol symbol)
         {
             if (symbol is null)