Rollup merge of #74336 - davidtwco:issue-73112-cross-crate-packed-type-diagnostic, r=estebank

typeck: use `item_name` in cross-crate packed diag

Fixes #73112.

This PR replaces the use of `expect_local` and `hir().get` to fetch the identifier for a ADT with `item_name` - which works across crates.

src/test/ui/issues/auxiliary/issue-73112.rs

@@ -0,0 +1,10 @@
+#[repr(transparent)]
+pub struct PageTableEntry {
+    entry: u64,
+}
+
+#[repr(align(4096))]
+#[repr(C)]
+pub struct PageTable {
+    entries: [PageTableEntry; 512],
+}

src/test/ui/issues/issue-73112.rs

@@ -0,0 +1,13 @@
+// aux-build:issue-73112.rs
+
+extern crate issue_73112;
+
+fn main() {
+    use issue_73112::PageTable;
+
+    #[repr(C, packed)]
+    struct SomeStruct {
+    //~^ ERROR packed type cannot transitively contain a `#[repr(align)]` type [E0588]
+        page_table: PageTable,
+    }
+}

src/test/ui/issues/issue-73112.stderr

@@ -0,0 +1,20 @@
+error[E0588]: packed type cannot transitively contain a `#[repr(align)]` type
+  --> $DIR/issue-73112.rs:9:5
+   |
+LL | /     struct SomeStruct {
+LL | |
+LL | |         page_table: PageTable,
+LL | |     }
+   | |_____^
+   |
+note: `PageTable` has a `#[repr(align)]` attribute
+  --> $DIR/auxiliary/issue-73112.rs:8:1
+   |
+LL | / pub struct PageTable {
+LL | |     entries: [PageTableEntry; 512],
+LL | | }
+   | |_^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0588`.