Don't throw exception for unresolved type (#46070)

* Don't throw exception for unresolved type

* Add Microsoft.AspNetCore.Http.HttpResults reference

src/Http/Http.Extensions/src/RequestDelegateFactory.cs

@@ -100,13 +100,7 @@ public static partial class RequestDelegateFactory
     // but users still need to assert on it as in https://github.com/dotnet/aspnetcore/issues/45063
     // so we temporarily work around this here by using reflection to get the actual type.
     private static readonly object? EmptyHttpResultInstance = Type.GetType("Microsoft.AspNetCore.Http.HttpResults.EmptyHttpResult, Microsoft.AspNetCore.Http.Results")?.GetProperty("Instance")?.GetValue(null, null);
-#if DEBUG
-    private static readonly NewExpression EmptyHttpResultValueTaskExpr = EmptyHttpResultInstance is not null
-            ? Expression.New(typeof(ValueTask<object>).GetConstructor(new[] { typeof(IResult) })!, Expression.Constant(EmptyHttpResultInstance))
-            : throw new UnreachableException("The EmptyHttpResult type could not be found.");
-#else
     private static readonly NewExpression EmptyHttpResultValueTaskExpr = Expression.New(typeof(ValueTask<object>).GetConstructor(new[] { typeof(IResult) })!, Expression.Constant(EmptyHttpResultInstance));
-#endif
     private static readonly ParameterExpression TempSourceStringExpr = ParameterBindingMethodCache.TempSourceStringExpr;
     private static readonly BinaryExpression TempSourceStringNotNullExpr = Expression.NotEqual(TempSourceStringExpr, Expression.Constant(null));
     private static readonly BinaryExpression TempSourceStringNullExpr = Expression.Equal(TempSourceStringExpr, Expression.Constant(null));

src/Http/Routing/test/UnitTests/Microsoft.AspNetCore.Routing.Tests.csproj

@@ -8,6 +8,7 @@
 
   <ItemGroup>
     <Reference Include="Microsoft.AspNetCore.Http" />
+    <Reference Include="Microsoft.AspNetCore.Http.Results" />
     <Reference Include="Microsoft.AspNetCore.Routing" />
     <Reference Include="Microsoft.AspNetCore.Http.Results" />
     <Reference Include="Microsoft.Extensions.DependencyInjection" />