Rust: Resolve Self path in trait type of implementation

Author: paldepind

rust/ql/lib/codeql/rust/internal/PathResolution.qll

@@ -373,6 +373,8 @@ abstract class ImplOrTraitItemNode extends ItemNode {
   /** Gets an item that may refer to this node using `Self`. */
   pragma[nomagic]
   ItemNode getAnItemInSelfScope() {
+    result = this
+    or
     result.getImmediateParent() = this
     or
     exists(ItemNode mid |

rust/ql/test/library-tests/path-resolution/main.rs

@@ -532,7 +532,7 @@ mod m23 {
 
     #[rustfmt::skip]
     impl Trait1<
-      Self // $ MISSING: item=I4
+      Self // $ item=I4
     > // $ item=I2
       for S { // $ item=I4
         fn f(&self) {

rust/ql/test/library-tests/path-resolution/path-resolution.expected

@@ -236,6 +236,7 @@ resolvePath
 | main.rs:517:21:517:29 | ...::A | main.rs:499:13:499:13 | A |
 | main.rs:518:21:518:28 | MyStruct | main.rs:502:9:502:28 | struct MyStruct |
 | main.rs:534:10:536:5 | Trait1::<...> | main.rs:524:5:529:5 | trait Trait1 |
+| main.rs:535:7:535:10 | Self | main.rs:531:5:531:13 | struct S |
 | main.rs:537:11:537:11 | S | main.rs:531:5:531:13 | struct S |
 | main.rs:545:17:545:17 | S | main.rs:531:5:531:13 | struct S |
 | main.rs:551:5:551:6 | my | main.rs:1:1:1:7 | mod my |