Rollup merge of #145660 - jbatez:darwin_objc, r=jdonszelmann,madsmtm,tmandry

initial implementation of the darwin_objc unstable feature

Tracking issue: https://github.com/rust-lang/rust/issues/145496

This feature makes it possible to reference Objective-C classes and selectors using the same ABI used by native Objective-C on Apple/Darwin platforms. Without it, Rust code interacting with Objective-C must resort to loading classes and selectors using costly string-based lookups at runtime. With it, these references can be loaded efficiently at dynamic load time.

r? ```@tmandry```

try-job: `*apple*`
try-job: `x86_64-gnu-nopt`

1 files changed, 27 insertions, 0 deletions

diff --git a/tests/codegen-llvm/auxiliary/darwin_objc_aux.rs b/tests/codegen-llvm/auxiliary/darwin_objc_aux.rs
new file mode 100644
index 00000000000..3c35d003c8a
--- /dev/null
+++ b/tests/codegen-llvm/auxiliary/darwin_objc_aux.rs
@@ -0,0 +1,27 @@
+#![crate_type = "lib"]
+#![feature(darwin_objc)]
+
+use std::os::darwin::objc;
+
+#[link(name = "Foundation", kind = "framework")]
+unsafe extern "C" {}
+
+#[inline(always)]
+pub fn inline_get_object_class() -> objc::Class {
+    objc::class!("NSObject")
+}
+
+#[inline(always)]
+pub fn inline_get_alloc_selector() -> objc::SEL {
+    objc::selector!("alloc")
+}
+
+#[inline(never)]
+pub fn never_inline_get_string_class() -> objc::Class {
+    objc::class!("NSString")
+}
+
+#[inline(never)]
+pub fn never_inline_get_init_selector() -> objc::SEL {
+    objc::selector!("init")
+}