Auto merge of #126049 - compiler-errors:rework-use, r=oli-obk

Rework `feature(precise_capturing)` to represent `use<...>` as a syntactical bound

Reworks `precise_capturing` for a recent lang-team consensus.

Specifically:

> The conclusion of the team is that we'll make use<..> a bound. That is, we'll support impl use<..> + Trait, impl Trait + use<..>, etc.

> For now, we will support at most one such bound in a list of bounds, and semantically we'll only support these bounds in the item bounds of RPIT-like impl Trait opaque types (i.e., in the places discussed in the RFC).

Lang decision in favor of this approach:

- https://github.com/rust-lang/rust/issues/125836#issuecomment-2151351849

Tracking:

- https://github.com/rust-lang/rust/issues/123432

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/ui/impl-trait/precise-capturing/duplicated-use.rs b/tests/ui/impl-trait/precise-capturing/duplicated-use.rs
new file mode 100644
index 00000000000..bfbdcdbf311
--- /dev/null
+++ b/tests/ui/impl-trait/precise-capturing/duplicated-use.rs
@@ -0,0 +1,10 @@
+//@ revisions: real pre_expansion
+//@[pre_expansion] check-pass
+
+#![feature(precise_capturing)]
+
+#[cfg(real)]
+fn hello<'a>() -> impl Sized + use<'a> + use<'a> {}
+//[real]~^ ERROR duplicate `use<...>` precise capturing syntax
+
+fn main() {}