Can't parse the name of a custom element name if the name is read from a variable

[matteematt]

Checklist

• Did you run the analyzer with the --dev flag to get more information?
• Did you create a minimal reproduction in the playground?

Completing the items above will greatly improve triaging time of your issue.

Expected behavior
When I create a custom element using the @customElement({name: ''}) syntax with Microsoft FAST, we should be able to hardcode the string in the object passed to the @customElement dectorator, but also be able to pass a variable name to name instead.