Auto merge of #54215 - kennytm:rollup, r=kennytm

Rollup of 8 pull requests

Successful merges:

 - #53218 (Add a implementation of `From` for converting `&'a Option<T>` into `Option<&'a T>`)
 - #54024 (Fix compiling some rustc crates to wasm)
 - #54095 (Rename all mentions of `nil` to `unit`)
 - #54173 (Suggest valid crate type if invalid crate type is found)
 - #54194 (Remove println!() statement from HashMap unit test)
 - #54203 (Fix the stable release of os_str_str_ref_eq)
 - #54207 (re-mark the never docs as unstable)
 - #54210 (Update Cargo)

Failed merges:

r? @ghost

1 files changed, 14 insertions, 0 deletions

diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index 53cf626bb1c..dfdc375765d 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -1062,6 +1062,20 @@ impl<T> From<T> for Option<T> {
     }
 }
 
+#[stable(feature = "option_ref_from_ref_option", since = "1.30.0")]
+impl<'a, T> From<&'a Option<T>> for Option<&'a T> {
+    fn from(o: &'a Option<T>) -> Option<&'a T> {
+        o.as_ref()
+    }
+}
+
+#[stable(feature = "option_ref_from_ref_option", since = "1.30.0")]
+impl<'a, T> From<&'a mut Option<T>> for Option<&'a mut T> {
+    fn from(o: &'a mut Option<T>) -> Option<&'a mut T> {
+        o.as_mut()
+    }
+}
+
 /////////////////////////////////////////////////////////////////////////////
 // The Option Iterators
 /////////////////////////////////////////////////////////////////////////////