EngineTest.ScenarioInterpreterNestedVariables is failing on .NET Core

This is passing on .NET Framework but failing on .NET Core.

ParameterExpression tmp = Expression.Parameter(typeof(object), "tmp");
var body = Expression.Lambda<Func<object>>(
    Expression.Block(
        Expression.Block(
            new[] { tmp },
            Expression.Assign(tmp, Expression.Constant(42, typeof(object)))
        ),
        Expression.Block(
            new[] { tmp },
            tmp
        )
    )
);

Debug.Assert(body.Compile()() is null);

I'm not sure which runtime is correct. If .NET Framework has the correct behavior then an issue should probably be filed for .NET Core (and Mono?). Note that CompilerHelpers.LightCompile(body)() is null so if .NET Core is correct should we "fix" the light compiler?

Start with EngineTest.ScenarioInterpreterNestedVariables and run the provided expression-tree example on .NET Framework, .NET Core, and Mono if available. Compare those results with CompilerHelpers.LightCompile(body)() and determine which behavior is expected; done means the runtime behavior is resolved and any required follow-up is identified.