binder: Order of declarations is backward from source order in union type

[sandersn]

discriminantPropertyCheck, discriminantsAndPrimitives

This is probably an intended or allowed difference that needs to be ignored by having both Strada and Corsa sort their symbol baseline declarations in source order.

[ahejlsberg]

Is there a repro? I'm pretty certain this is intended given the new type ordering.

[sandersn]

The two compiler tests

• discriminantPropertyCheck
• discriminantsAndPrimitives

Probably one or both of Corsa and Strada need to be able to produce baselines in "compatibility mode" that does things like sorting baseline declarations (plus overlooking other diffs).

[jakebailey]

This is now fixed, given we diff against tsc that's also been modified for the union ordering.