Rollup merge of #124067 - RalfJung:weak-lang-items, r=davidtwco

weak lang items are not allowed to be #[track_caller]

For instance the panic handler will be called via this import
```rust
        extern "Rust" {
            #[lang = "panic_impl"]
            fn panic_impl(pi: &PanicInfo<'_>) -> !;
        }
```
A `#[track_caller]` would add an extra argument and thus make this the wrong signature.

The 2nd commit is a consistency rename; based on the docs [here](https://doc.rust-lang.org/unstable-book/language-features/lang-items.html) and [here](https://rustc-dev-guide.rust-lang.org/lang-items.html) I figured "lang item" is more widely used. (In the compiler output, "lang item" and "language item" seem to be pretty even.)

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index 596da58b091..c4ab4eb2657 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -1208,7 +1208,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
         tcx.arena.alloc_from_iter(self.root.stability_implications.decode(self))
     }
 
-    /// Iterates over the language items in the given crate.
+    /// Iterates over the lang items in the given crate.
     fn get_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [(DefId, LangItem)] {
         tcx.arena.alloc_from_iter(
             self.root