Rollup of 2 pull requests

compiler/rustc_hir_analysis/src/coherence/builtin.rs

@@ -153,6 +153,8 @@ fn visit_implementation_of_unpin(checker: &Checker<'_>) -> Result<(), ErrorGuara
                 }));
             }
             ty::Adt(_, _) => {}
+            // `extern type`s have no fields, so they can't be structurally pinned.
+            ty::Foreign(_) => {}
             _ => {
                 return Err(tcx.dcx().span_delayed_bug(span, "impl of `Unpin` for a non-adt type"));
             }

compiler/rustc_target/src/spec/targets/aarch64_unknown_fuchsia.rs

@@ -5,7 +5,7 @@ use crate::spec::{
 pub(crate) fn target() -> Target {
     let mut base = base::fuchsia::opts();
     base.cpu = "generic".into();
-    base.features = "+v8a,+crc,+aes,+sha2,+neon".into();
+    base.features = "+v8a,+crc,+aes,+sha2,+neon,+fix-cortex-a53-835769".into();
     base.max_atomic_width = Some(128);
     base.stack_probes = StackProbeType::Inline;
     base.supported_sanitizers = SanitizerSet::ADDRESS

tests/codegen-llvm/aarch64-fuchsia-target-features.rs

@@ -0,0 +1,14 @@
+//@ add-minicore
+//@ compile-flags: --crate-type=rlib --target=aarch64-unknown-fuchsia
+//@ needs-llvm-components: aarch64
+
+// CHECK: attributes #0 = { {{.*}}"target-features"="{{.*}}+fix-cortex-a53-835769{{.*}}" }
+
+#![feature(no_core, lang_items)]
+#![no_core]
+
+extern crate minicore;
+use minicore::*;
+
+#[no_mangle]
+pub fn test() {}

tests/ui/pin-ergonomics/impl-unpin-extern-type.rs

@@ -0,0 +1,18 @@
+//! Verify that a local `extern type` can manually implement `Unpin` with `pin_ergonomics` enabled.
+//! Unlike a `#[pin_v2]` ADT, an extern type has no fields that could be structually pinned.
+//!
+//! Regression test for <https://github.com/rust-lang/rust/issues/155053>.
+
+//@ check-pass
+
+#![feature(pin_ergonomics)]
+#![feature(extern_types)]
+#![allow(incomplete_features)]
+
+unsafe extern "C" {
+    type ExternType;
+}
+
+impl Unpin for ExternType {}
+
+fn main() {}