don't use generator witness for implied bounds

[aliemjay]

... and also don't draw implied bounds from the output type of generators and closures. FnDef is still an exception so that we keep supporting (edit: reverted):

fn absurd<T>() -> Option<&'static T> { None }

TODO open issues for the bugs fixed here. In the mean time there is tests/ui/async-await/generator-wf-check.rs

r? @ghost

[aliemjay]

@bors try

[bors]

⌛ Trying commit d06f509 with merge c998a0147310b58319f4172e953bf2a9c5c5c5fa...

[bors]

💔 Test failed - checks-actions

[aliemjay]

@bors try

[bors]

⌛ Trying commit 7d78764 with merge 3ba53ac6e3a6cb265590cf8c832c06260d624b6e...

[bors]

☀️ Try build successful - checks-actions
Build commit: 3ba53ac6e3a6cb265590cf8c832c06260d624b6e (3ba53ac6e3a6cb265590cf8c832c06260d624b6e)

[aliemjay]

@craterbot check

[craterbot]

👌 Experiment pr-115173 created and queued.
🤖 Automatically detected try build 3ba53ac6e3a6cb265590cf8c832c06260d624b6e
🔍 You can check out the queue and this experiment's details.

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[craterbot]

🚧 Experiment pr-115173 is now running

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[craterbot]

🎉 Experiment pr-115173 is completed!
📊 5 regressed and 3 fixed (354298 total)
📰 Open the full report.

⚠️ If you notice any spurious failure please add them to the blacklist!
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[Dylan-DPC]

@aliemjay any updates on this?

[Dylan-DPC]

Closing this as inactive. Feel free to reöpen this pr or create a new pr if you get the time to work on this. Thanks