Auto merge of #83360 - Dylan-DPC:rollup-17xulpv, r=Dylan-DPC

Rollup of 9 pull requests

Successful merges:

 - #80193 (stabilize `feature(osstring_ascii)`)
 - #80771 (Make NonNull::as_ref (and friends) return refs with unbound lifetimes)
 - #81607 (Implement TrustedLen and TrustedRandomAccess for Range<integer>, array::IntoIter, VecDequeue's iterators)
 - #82554 (Fix invalid slice access in String::retain)
 - #82686 (Move `std::sys::unix::platform` to `std::sys::unix::ext`)
 - #82771 (slice: Stabilize IterMut::as_slice.)
 - #83329 (Cleanup LLVM debuginfo module docs)
 - #83336 (Fix ICE with `use clippy:🅰️:b;`)
 - #83350 (Download a more recent LLVM version if `src/version` is modified)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

src/bootstrap/bootstrap.py

@@ -463,6 +463,8 @@ class RustBuild(object):
                 "--",
                 "{}/src/llvm-project".format(top_level),
                 "{}/src/bootstrap/download-ci-llvm-stamp".format(top_level),
+                # the LLVM shared object file is named `LLVM-12-rust-{version}-nightly`
+                "{}/src/version".format(top_level)
             ]).decode(sys.getdefaultencoding()).strip()
             llvm_assertions = self.get_toml('assertions', 'llvm') == 'true'
             llvm_root = self.llvm_root()

src/test/ui/imports/tool-mod-child.rs

@@ -0,0 +1,7 @@
+use clippy::a; //~ ERROR unresolved import `clippy`
+use clippy::a::b; //~ ERROR failed to resolve: maybe a missing crate `clippy`?
+
+use rustdoc::a; //~ ERROR unresolved import `rustdoc`
+use rustdoc::a::b; //~ ERROR failed to resolve: maybe a missing crate `rustdoc`?
+
+fn main() {}

src/test/ui/imports/tool-mod-child.stderr

@@ -0,0 +1,28 @@
+error[E0433]: failed to resolve: maybe a missing crate `clippy`?
+  --> $DIR/tool-mod-child.rs:2:5
+   |
+LL | use clippy::a::b;
+   |     ^^^^^^ maybe a missing crate `clippy`?
+
+error[E0432]: unresolved import `clippy`
+  --> $DIR/tool-mod-child.rs:1:5
+   |
+LL | use clippy::a;
+   |     ^^^^^^ maybe a missing crate `clippy`?
+
+error[E0433]: failed to resolve: maybe a missing crate `rustdoc`?
+  --> $DIR/tool-mod-child.rs:5:5
+   |
+LL | use rustdoc::a::b;
+   |     ^^^^^^^ maybe a missing crate `rustdoc`?
+
+error[E0432]: unresolved import `rustdoc`
+  --> $DIR/tool-mod-child.rs:4:5
+   |
+LL | use rustdoc::a;
+   |     ^^^^^^^ maybe a missing crate `rustdoc`?
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0432, E0433.
+For more information about an error, try `rustc --explain E0432`.