Auto merge of #1964 - RalfJung:rustup, r=RalfJung

rustup

Let's hope we can finally get CI green again...

rust-version

@@ -1 +1 @@
-e19ca1d946269f7b7eb13171531caf2e16f42076
+a7f375789bab1a4e4a291c963081a8ca7d2b6bd7

src/shims/posix/macos/dlsym.rs

@@ -17,6 +17,7 @@ impl Dlsym {
     pub fn from_str(name: &str) -> InterpResult<'static, Option<Dlsym>> {
         Ok(match name {
             "getentropy" => Some(Dlsym::getentropy),
+            "openat" => None, // std has a fallback for this
             _ => throw_unsup_format!("unsupported macOS dlsym: {}", name),
         })
     }