Rollup merge of #79968 - bjorn3:better_drop_glue_debuginfo, r=matthewjasper

Improve core::ptr::drop_in_place debuginfo

* Use span of the dropped type as function span when possible.
* Rename symbol from `core::ptr::drop_in_place::$hash` to `{{drop}}::<$TYPE>::$hash`.

Fixes #77465

(I haven't yet updated the tests)

compiler/rustc_symbol_mangling/src/legacy.rs

@@ -56,7 +56,15 @@ pub(super) fn mangle(
     let hash = get_symbol_hash(tcx, instance, instance_ty, instantiating_crate);
 
     let mut printer = SymbolPrinter { tcx, path: SymbolPath::new(), keep_within_component: false }
-        .print_def_path(def_id, &[])
+        .print_def_path(
+            def_id,
+            if let ty::InstanceDef::DropGlue(_, _) = instance.def {
+                // Add the name of the dropped type to the symbol name
+                &*instance.substs
+            } else {
+                &[]
+            },
+        )
         .unwrap();
 
     if let ty::InstanceDef::VtableShim(..) = instance.def {