Return ident for ExprField and PatField HIR nodes

Author: gurry

compiler/rustc_hir/src/hir.rs

@@ -3729,6 +3729,8 @@ impl<'hir> Node<'hir> {
             Node::Lifetime(lt) => Some(lt.ident),
             Node::GenericParam(p) => Some(p.name.ident()),
             Node::TypeBinding(b) => Some(b.ident),
+            Node::PatField(f) => Some(f.ident),
+            Node::ExprField(f) => Some(f.ident),
             Node::Param(..)
             | Node::AnonConst(..)
             | Node::ConstBlock(..)
@@ -3737,8 +3739,6 @@ impl<'hir> Node<'hir> {
             | Node::Block(..)
             | Node::Ctor(..)
             | Node::Pat(..)
-            | Node::PatField(..)
-            | Node::ExprField(..)
             | Node::Arm(..)
             | Node::Local(..)
             | Node::Crate(..)

tests/ui/attributes/issue-115264-expr-field.rs

@@ -0,0 +1,17 @@
+// Regression test for issue 115264
+// Tests that retrieving the ident of the X::foo field
+// in main() does not cause an ICE
+
+// check-pass
+
+#[allow(dead_code)]
+struct X {
+    foo: i32,
+}
+
+fn main() {
+    let _ = X {
+        #[doc(alias = "StructItem")]
+        foo: 123,
+    };
+}

tests/ui/attributes/issue-115264-pat-field.rs

@@ -0,0 +1,19 @@
+// Regression test for issue 115264
+// Tests that retrieving the ident of 'foo' variable in
+// the pattern inside main() does not cause an ICE
+
+// check-pass
+
+struct X {
+    foo: i32,
+}
+
+#[allow(unused_variables)]
+fn main() {
+    let X {
+        #[doc(alias = "StructItem")]
+        foo
+    } = X {
+        foo: 123
+    };
+}