Auto merge of #76176 - marmeladema:fix-closure-path-printing, r=eddyb

Move from {{closure}}#0 syntax to {closure#0} for (def) path components

Part of #70334

I followed the approach described by `@eddyb` and introduced a `DefPathDataName` enum.
To preserve compatibility, in various places, I had to rely on formatting manually by calling `format!("{{{{{}}}}}", namespace)`.

My questions are:
* Do we want to convert for places to use the new naming scheme? Or shall I re-add `DefPathData::as_symbol` but renamed as `DefPathData::as_legacy_symbol` to avoid manually allocating the legacy symbols?
* Do we want to `impl Display for DisambiguatedDefPathData` to avoid manually calling `write!(s, "{{{}#{}}}", namespace, component.disambiguator)`?
* We might also want to improve naming for `DefPathDataName` and `DefPathData::get_name`

r? `@eddyb`

1 files changed, 10 insertions, 3 deletions

diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/namespace.rs b/compiler/rustc_codegen_llvm/src/debuginfo/namespace.rs
index d1a55335c44..9945d4f4282 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/namespace.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/namespace.rs
@@ -27,11 +27,18 @@ pub fn item_namespace(cx: &CodegenCx<'ll, '_>, def_id: DefId) -> &'ll DIScope {
         .parent
         .map(|parent| item_namespace(cx, DefId { krate: def_id.krate, index: parent }));
 
+    let crate_name_as_str;
+    let name_to_string;
     let namespace_name = match def_key.disambiguated_data.data {
-        DefPathData::CrateRoot => cx.tcx.crate_name(def_id.krate),
-        data => data.as_symbol(),
+        DefPathData::CrateRoot => {
+            crate_name_as_str = cx.tcx.crate_name(def_id.krate).as_str();
+            &*crate_name_as_str
+        }
+        data => {
+            name_to_string = data.to_string();
+            &*name_to_string
+        }
     };
-    let namespace_name = namespace_name.as_str();
 
     let scope = unsafe {
         llvm::LLVMRustDIBuilderCreateNameSpace(