Merge commit 'e4fe941b11' into subtree-update_cg_gcc_2023-10-25

compiler/rustc_codegen_gcc/tests/run/volatile.rs

@@ -0,0 +1,26 @@
+// Compiler:
+//
+// Run-time:
+//   status: 0
+
+use std::mem::MaybeUninit;
+
+#[derive(Debug)]
+struct Struct {
+    pointer: *const (),
+    func: unsafe fn(*const ()),
+}
+
+fn func(ptr: *const ()) {
+}
+
+fn main() {
+    let mut x = MaybeUninit::<&Struct>::uninit();
+    x.write(&Struct {
+        pointer: std::ptr::null(),
+        func,
+    });
+    let x = unsafe { x.assume_init() };
+    let value = unsafe { (x as *const Struct).read_volatile() };
+    println!("{:?}", value);
+}