Gray dead code inside a function

[HKalbasi]

Typescript language server will highlight dead code after return or similar in gray. Since such dead code is not represented in MIR, we can implement this feature by just graying everything and then un-gray ast nodes that are represented in MIR.

[HKalbasi]

The highlighting functionality could be reused by #14668 as well.

[rustbot]

Error: Parsing assign command in comment failed: ...' assign' | error: specify user to assign to at >| ''...

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[alibektas]

@rustbot claim

[alibektas]

I want to give this a shot, though mir is a field alien to me. Let's see.

[Shourya742]

Hey @Veykril, has this already been implemented? The functionality mentioned in the issue seems to be present in RA.

[ChayimFriedman2]

It might be easier to do it via inference diverging check than via MIR.