Add global:: to default usings

src/Compiler/Microsoft.AspNetCore.Razor.Language/src/Extensions/DesignTimeDirectivePass.cs

@@ -52,7 +52,7 @@ public override void VisitClassDeclaration(ClassDeclarationIntermediateNode node
                         new IntermediateToken()
                         {
                             Kind = TokenKind.CSharp,
-                            Content = $"private static {typeof(object).FullName} {DesignTimeVariable} = null;",
+                            Content = $"private static object {DesignTimeVariable} = null;",
                         }
                     }
             });

src/Compiler/Microsoft.AspNetCore.Razor.Language/src/Extensions/DesignTimeDirectiveTargetExtension.cs

@@ -54,10 +54,7 @@ private void WriteDesignTimeDirectiveToken(CodeRenderingContext context, DesignT
         }
 
         // Wrap the directive token in a lambda to isolate variable names.
-        context.CodeWriter
-            .Write("((")
-            .Write(typeof(Action).FullName)
-            .Write(")(");
+        context.CodeWriter.Write("((global::System.Action)(");
         using (context.CodeWriter.BuildLambda())
         {
             var originalIndent = context.CodeWriter.CurrentIndent;