Fix object literal shorthand code generation bug

[Conduitry]

Fixes #3929.

[Conduitry]

The test failures have informed me that apparently I broke the shorthand syntax optimization in certain situations which apparently were not tested for in code-red. Don't merge this - I'll take a look in a bit.

[Conduitry]

Boring news flash: The changes arose because code-red is being passed { ctx: #ctx }, and so the name ctx doesn't equal #ctx by the time we're seeing whether we can use the shorthand notation, and #ctx only gets turned into ctx afterwards. I guess there was a reason after all for calling handle() on the value and then looking at that before deciding about the shorthand notation rather than just looking directly at the AST. In conclusion: bleh.