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, 3 insertions, 2 deletions

diff --git a/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs b/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
index 0c0f1bc681c..45ecb793387 100644
--- a/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
+++ b/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
@@ -5,6 +5,8 @@ use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty::{self, subst::SubstsRef, Ty, TyCtxt};
 
+use std::fmt::Write;
+
 // Compute the name of the type as it should be stored in debuginfo. Does not do
 // any caching, i.e., calling the function twice with the same type will also do
 // the work twice. The `qualified` parameter only affects the first level of the
@@ -228,8 +230,7 @@ pub fn push_debuginfo_type_name<'tcx>(
         if qualified {
             output.push_str(&tcx.crate_name(def_id.krate).as_str());
             for path_element in tcx.def_path(def_id).data {
-                output.push_str("::");
-                output.push_str(&path_element.data.as_symbol().as_str());
+                write!(output, "::{}", path_element.data).unwrap();
             }
         } else {
             output.push_str(&tcx.item_name(def_id).as_str());