Auto merge of #53832 - pietroalbini:rollup, r=pietroalbini

Rollup of 20 pull requests

Successful merges:

 - #51760 (Add another PartialEq example)
 - #53113 (Add example for Cow)
 - #53129 (remove `let x = baz` which was obscuring the real error)
 - #53389 (document effect of join on memory ordering)
 - #53472 (Use FxHash{Map,Set} instead of the default Hash{Map,Set} everywhere in rustc.)
 - #53476 (Add partialeq implementation for TryFromIntError type)
 - #53513 (Force-inline `shallow_resolve` at its hottest call site.)
 - #53655 (set applicability)
 - #53702 (Fix stabilisation version for macro_vis_matcher.)
 - #53727 (Do not suggest dereferencing in macro)
 - #53732 (save-analysis: Differentiate foreign functions and statics.)
 - #53740 (add llvm-readobj to llvm-tools-preview)
 - #53743 (fix a typo: taget_env -> target_env)
 - #53747 (Rustdoc fixes)
 - #53753 (expand keep-stage --help text)
 - #53756 (Fix typo in comment)
 - #53768 (move file-extension based .gitignore down to src/)
 - #53785 (Fix a comment in src/libcore/slice/mod.rs)
 - #53786 (Replace usages of 'bad_style' with 'nonstandard_style'.)
 - #53806 (Fix UI issues on Implementations on Foreign types)

Failed merges:

r? @ghost

11 files changed, 41 insertions, 35 deletions

diff --git a/src/libstd/os/mod.rs b/src/libstd/os/mod.rs
index c384ec9168a..6d8298f01cd 100644
--- a/src/libstd/os/mod.rs
+++ b/src/libstd/os/mod.rs
@@ -11,7 +11,7 @@
 //! OS-specific functionality.
 
 #![stable(feature = "os", since = "1.0.0")]
-#![allow(missing_docs, bad_style, missing_debug_implementations)]
+#![allow(missing_docs, nonstandard_style, missing_debug_implementations)]
 
 cfg_if! {
     if #[cfg(dox)] {
diff --git a/src/libstd/sys/redox/mod.rs b/src/libstd/sys/redox/mod.rs
index 4352b72c307..f943257c687 100644
--- a/src/libstd/sys/redox/mod.rs
+++ b/src/libstd/sys/redox/mod.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(dead_code, missing_docs, bad_style)]
+#![allow(dead_code, missing_docs, nonstandard_style)]
 
 use io::{self, ErrorKind};
 
diff --git a/src/libstd/sys/unix/fd.rs b/src/libstd/sys/unix/fd.rs
index 4830e38d6a9..12e14734ff5 100644
--- a/src/libstd/sys/unix/fd.rs
+++ b/src/libstd/sys/unix/fd.rs
@@ -282,7 +282,7 @@ impl Drop for FileDesc {
         // reason for this is that if an error occurs we don't actually know if
         // the file descriptor was closed or not, and if we retried (for
         // something like EINTR), we might close another valid file descriptor
-        // (opened after we closed ours.
+        // opened after we closed ours.
         let _ = unsafe { libc::close(self.fd) };
     }
 }
diff --git a/src/libstd/sys/unix/mod.rs b/src/libstd/sys/unix/mod.rs
index c738003caf1..2b9fbc9ef39 100644
--- a/src/libstd/sys/unix/mod.rs
+++ b/src/libstd/sys/unix/mod.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(missing_docs, bad_style)]
+#![allow(missing_docs, nonstandard_style)]
 
 use io::{self, ErrorKind};
 use libc;
diff --git a/src/libstd/sys/unix/net.rs b/src/libstd/sys/unix/net.rs
index 8c73fe8c612..2d10541752c 100644
--- a/src/libstd/sys/unix/net.rs
+++ b/src/libstd/sys/unix/net.rs
@@ -395,30 +395,3 @@ fn on_resolver_failure() {
 
 #[cfg(not(target_env = "gnu"))]
 fn on_resolver_failure() {}
-
-#[cfg(all(test, taget_env = "gnu"))]
-mod test {
-    use super::*;
-
-    #[test]
-    fn test_res_init() {
-        // This mostly just tests that the weak linkage doesn't panic wildly...
-        res_init_if_glibc_before_2_26().unwrap();
-    }
-
-    #[test]
-    fn test_parse_glibc_version() {
-        let cases = [
-            ("0.0", Some((0, 0))),
-            ("01.+2", Some((1, 2))),
-            ("3.4.5.six", Some((3, 4))),
-            ("1", None),
-            ("1.-2", None),
-            ("1.foo", None),
-            ("foo.1", None),
-        ];
-        for &(version_str, parsed) in cases.iter() {
-            assert_eq!(parsed, parse_glibc_version(version_str));
-        }
-    }
-}
diff --git a/src/libstd/sys/unix/os.rs b/src/libstd/sys/unix/os.rs
index f8f0bbd5bc2..971e6501c2c 100644
--- a/src/libstd/sys/unix/os.rs
+++ b/src/libstd/sys/unix/os.rs
@@ -569,3 +569,30 @@ fn parse_glibc_version(version: &str) -> Option<(usize, usize)> {
         _ => None
     }
 }
+
+#[cfg(all(test, target_env = "gnu"))]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_glibc_version() {
+        // This mostly just tests that the weak linkage doesn't panic wildly...
+        glibc_version();
+    }
+
+    #[test]
+    fn test_parse_glibc_version() {
+        let cases = [
+            ("0.0", Some((0, 0))),
+            ("01.+2", Some((1, 2))),
+            ("3.4.5.six", Some((3, 4))),
+            ("1", None),
+            ("1.-2", None),
+            ("1.foo", None),
+            ("foo.1", None),
+        ];
+        for &(version_str, parsed) in cases.iter() {
+            assert_eq!(parsed, parse_glibc_version(version_str));
+        }
+    }
+}
diff --git a/src/libstd/sys/wasm/net.rs b/src/libstd/sys/wasm/net.rs
index e7476ab37f7..03a5b2d779e 100644
--- a/src/libstd/sys/wasm/net.rs
+++ b/src/libstd/sys/wasm/net.rs
@@ -297,7 +297,7 @@ pub fn lookup_host(_: &str) -> io::Result<LookupHost> {
     unsupported()
 }
 
-#[allow(bad_style)]
+#[allow(nonstandard_style)]
 pub mod netc {
     pub const AF_INET: u8 = 0;
     pub const AF_INET6: u8 = 1;
diff --git a/src/libstd/sys/windows/c.rs b/src/libstd/sys/windows/c.rs
index e514a56dcc4..8a744519e91 100644
--- a/src/libstd/sys/windows/c.rs
+++ b/src/libstd/sys/windows/c.rs
@@ -10,7 +10,7 @@
 
 //! C definitions used by libnative that don't belong in liblibc
 
-#![allow(bad_style)]
+#![allow(nonstandard_style)]
 #![cfg_attr(test, allow(dead_code))]
 #![unstable(issue = "0", feature = "windows_c")]
 
diff --git a/src/libstd/sys/windows/mod.rs b/src/libstd/sys/windows/mod.rs
index ccf79de909f..31ef9fa2bed 100644
--- a/src/libstd/sys/windows/mod.rs
+++ b/src/libstd/sys/windows/mod.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(missing_docs, bad_style)]
+#![allow(missing_docs, nonstandard_style)]
 
 use ptr;
 use ffi::{OsStr, OsString};
diff --git a/src/libstd/sys/windows/os.rs b/src/libstd/sys/windows/os.rs
index b9448243559..29ea82c2053 100644
--- a/src/libstd/sys/windows/os.rs
+++ b/src/libstd/sys/windows/os.rs
@@ -10,7 +10,7 @@
 
 //! Implementation of `std::os` functionality for Windows
 
-#![allow(bad_style)]
+#![allow(nonstandard_style)]
 
 use os::windows::prelude::*;
 
diff --git a/src/libstd/thread/mod.rs b/src/libstd/thread/mod.rs
index 61c6084a250..a7c7dbb1b40 100644
--- a/src/libstd/thread/mod.rs
+++ b/src/libstd/thread/mod.rs
@@ -1310,11 +1310,17 @@ impl<T> JoinHandle<T> {
 
     /// Waits for the associated thread to finish.
     ///
+    /// In terms of [atomic memory orderings],  the completion of the associated
+    /// thread synchronizes with this function returning. In other words, all
+    /// operations performed by that thread are ordered before all
+    /// operations that happen after `join` returns.
+    ///
     /// If the child thread panics, [`Err`] is returned with the parameter given
     /// to [`panic`].
     ///
     /// [`Err`]: ../../std/result/enum.Result.html#variant.Err
     /// [`panic`]: ../../std/macro.panic.html
+    /// [atomic memory orderings]: ../../std/sync/atomic/index.html
     ///
     /// # Panics
     ///