Auto merge of #141473 - matthiaskrgr:rollup-y3vhivo, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #140790 (Enable xray support for Mac)
 - #141405 (GetUserProfileDirectoryW is now documented to always store the size)
 - #141413 (Make #[cfg(version)] respect RUSTC_OVERRIDE_VERSION_STRING)
 - #141427 (Disable `triagebot`'s `glacier` handler)
 - #141429 (Dont walk into unsafe binders when emiting error for non-structural type match)
 - #141438 (Do not try to confirm non-dyn compatible method)
 - #141444 (Improve CONTRIBUTING.md grammar and clarity)
 - #141446 (Add 2nd Solaris target maintainer)

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

Author: bors

CONTRIBUTING.md

@@ -5,7 +5,7 @@ and we appreciate all of them.
 
 The best way to get started is by asking for help in the [#new
 members](https://rust-lang.zulipchat.com/#narrow/stream/122652-new-members)
-Zulip stream. We have lots of docs below of how to get started on your own, but
+Zulip stream. We have a lot of documentation below on how to get started on your own, but
 the Zulip stream is the best place to *ask* for help.
 
 Documentation for contributing to the compiler or tooling is located in the [Guide to Rustc
@@ -14,7 +14,7 @@ standard library in the [Standard library developers Guide][std-dev-guide], comm
 
 ## Making changes to subtrees and submodules
 
-For submodules, changes need to be made against the repository corresponding the
+For submodules, changes need to be made against the repository corresponding to the
 submodule, and not the main `rust-lang/rust` repository.
 
 For subtrees, prefer sending a PR against the subtree's repository if it does
@@ -25,15 +25,15 @@ rustc-dev-guide change that does not accompany a compiler change).
 
 The [rustc-dev-guide] is meant to help document how rustc –the Rust compiler– works,
 as well as to help new contributors get involved in rustc development. It is recommended
-to read and understand the [rustc-dev-guide] before making a contribution. This guide
+that you read and understand the [rustc-dev-guide] before making a contribution. This guide
 talks about the different bots in the Rust ecosystem, the Rust development tools,
 bootstrapping, the compiler architecture, source code representation, and more.
 
 ## [Getting help](https://rustc-dev-guide.rust-lang.org/getting-started.html#asking-questions)
 
 There are many ways you can get help when you're stuck. Rust has many platforms for this:
 [internals], [rust-zulip], and [rust-discord]. It is recommended to ask for help on
-the [rust-zulip], but any of these platforms are a great way to seek help and even
+the [rust-zulip], but any of these platforms are great ways to seek help and even
 find a mentor! You can learn more about asking questions and getting help in the
 [Asking Questions](https://rustc-dev-guide.rust-lang.org/getting-started.html#asking-questions) chapter of the [rustc-dev-guide].
 

compiler/rustc_attr_data_structures/src/version.rs

@@ -1,4 +1,5 @@
 use std::fmt::{self, Display};
+use std::sync::OnceLock;
 
 use rustc_macros::{
     Decodable, Encodable, HashStable_Generic, PrintAttribute, current_rustc_version,
@@ -16,8 +17,29 @@ pub struct RustcVersion {
 
 impl RustcVersion {
     pub const CURRENT: Self = current_rustc_version!();
+    pub fn current_overridable() -> Self {
+        *CURRENT_OVERRIDABLE.get_or_init(|| {
+            if let Ok(override_var) = std::env::var("RUSTC_OVERRIDE_VERSION_STRING")
+                && let Some(override_) = Self::parse_str(&override_var)
+            {
+                override_
+            } else {
+                Self::CURRENT
+            }
+        })
+    }
+    fn parse_str(value: &str) -> Option<Self> {
+        // Ignore any suffixes such as "-dev" or "-nightly".
+        let mut components = value.split('-').next().unwrap().splitn(3, '.');
+        let major = components.next()?.parse().ok()?;
+        let minor = components.next()?.parse().ok()?;
+        let patch = components.next().unwrap_or("0").parse().ok()?;
+        Some(RustcVersion { major, minor, patch })
+    }
 }
 
+static CURRENT_OVERRIDABLE: OnceLock<RustcVersion> = OnceLock::new();
+
 impl Display for RustcVersion {
     fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(formatter, "{}.{}.{}", self.major, self.minor, self.patch)