[RFC PATCH 1/2] rust: list: Implement normal initializer for ListLinks

[I Hsin Cheng <richard120310@gmail.com>]

Currently ListLinks only supports to create an initializer through
"new()", which will need further initialization because the return type
of "new()" is "impl Pininit<Self>". Not even "ListLinksSlefPtr" use the
method to create a new instance of "ListLinks".

Implement a normal method to create a new instance of type "ListLinks".
This may be redundant as long as there exist a convenient and proper way
to deal with "ListLinks::new()".

For now it's introduce for the simplicity of examples in the following
patches.

Signed-off-by: I Hsin Cheng <richard120310@gmail.com>
---
 rust/kernel/list.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/rust/kernel/list.rs b/rust/kernel/list.rs
index fb93330f4af4..57d75ca16434 100644
--- a/rust/kernel/list.rs
+++ b/rust/kernel/list.rs
@@ -158,6 +158,16 @@ unsafe impl<const ID: u64> Send for ListLinks<ID> {}
 unsafe impl<const ID: u64> Sync for ListLinks<ID> {}
 
 impl<const ID: u64> ListLinks<ID> {
+    /// Create a new instance of this type.
+    pub fn new_link() -> Self {
+        ListLinks {
+            inner: Opaque::new(ListLinksFields {
+                prev: ptr::null_mut(),
+                next: ptr::null_mut(),
+            }),
+        }
+    }
+
     /// Creates a new initializer for this type.
     pub fn new() -> impl PinInit<Self> {
         // INVARIANT: Pin-init initializers can't be used on an existing `Arc`, so this value will
-- 
2.43.0