Broken expression node at the end of a cell breaks the AST

[minestarks]

In VS Code, in a Jupyter notebook cell, type some code that ends with an incomplete expression, like:

%%qsharp

function Foo() : Unit {}
let abc = Foo();
let x = 

Try using editor features like hover, go-to-def for any of the valid code above the last line.

Expected: Code above the last broken line works

Actual: The entire cell seems to be broken.