Auto merge of rust-lang#104387 - Manishearth:rollup-9e551p5, r=Manishearth

Rollup of 9 pull requests

Successful merges:

 - rust-lang#103709 (ci: Upgrade dist-x86_64-netbsd to NetBSD 9.0)
 - rust-lang#103744 (Upgrade cc for working is_flag_supported on cross-compiles)
 - rust-lang#104105 (llvm: dwo only emitted when object code emitted)
 - rust-lang#104158 (Return .efi extension for EFI executable)
 - rust-lang#104181 (Add a few known-bug tests)
 - rust-lang#104266 (Regression test for coercion of mut-ref to dyn-star)
 - rust-lang#104300 (Document `Path::parent` behavior around relative paths)
 - rust-lang#104304 (Enable profiler in dist-s390x-linux)
 - rust-lang#104362 (Add `delay_span_bug` to `AttrWrapper::take_for_recovery`)

Failed merges:

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

Author: bors

std/src/path.rs

@@ -2142,7 +2142,10 @@ impl Path {
 
     /// Returns the `Path` without its final component, if there is one.
     ///
-    /// Returns [`None`] if the path terminates in a root or prefix.
+    /// This means it returns `Some("")` for relative paths with one component.
+    ///
+    /// Returns [`None`] if the path terminates in a root or prefix, or if it's
+    /// the empty string.
     ///
     /// # Examples
     ///
@@ -2156,6 +2159,14 @@ impl Path {
     /// let grand_parent = parent.parent().unwrap();
     /// assert_eq!(grand_parent, Path::new("/"));
     /// assert_eq!(grand_parent.parent(), None);
+    ///
+    /// let relative_path = Path::new("foo/bar");
+    /// let parent = relative_path.parent();
+    /// assert_eq!(parent, Some(Path::new("foo")));
+    /// let grand_parent = parent.and_then(Path::parent);
+    /// assert_eq!(grand_parent, Some(Path::new("")));
+    /// let great_grand_parent = grand_parent.and_then(Path::parent);
+    /// assert_eq!(great_grand_parent, None);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[doc(alias = "dirname")]

unwind/Cargo.toml

@@ -20,7 +20,7 @@ compiler_builtins = "0.1.0"
 cfg-if = "1.0"
 
 [build-dependencies]
-cc = "1.0.69"
+cc = "1.0.76"
 
 [features]