Add a test

Author: compiler-errors

tests/codegen/slice-init.rs

@@ -89,6 +89,20 @@ pub fn option_none_init() -> [Option<u8>; N] {
 [None;N]
 }
 
+use std::mem::MaybeUninit;
+
+// FIXME: This could be optimized into a memset.
+// Regression test for <https://github.com/rust-lang/rust/issues/137892>.
+#[no_mangle]
+pubfnhalf_uninit() -> [(u128,MaybeUninit<u128>);N]{
+// CHECK-NOT: select
+// CHECK: br label %repeat_loop_header{{.*}}
+// CHECK-NOT: switch
+// CHECK: icmp
+// CHECK-NOT: call void @llvm.memset.p0
+[const{(0,MaybeUninit::uninit())};N]
+}
+
 // Use an opaque function to prevent rustc from removing useless drops.
 #[inline(never)]
 pubfnopaque(_:implSized){}