[heap] Update HeapStats map type

Use `const void*` to signal that we are not hashing for the
`char*` contents.

Change-Id: Ib8c31e293ec1e57a7799a68cfd2d59ce39076d43
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3190108
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Auto-Submit: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77119}

src/heap/cppgc/heap-statistics-collector.cc

@@ -73,7 +73,7 @@ void FinalizeSpace(HeapStatistics* stats,
 }
 
 void RecordObjectType(
-    std::unordered_map<const char*, size_t>& type_map,
+    std::unordered_map<const void*, size_t>& type_map,
     std::vector<HeapStatistics::ObjectStatsEntry>& object_statistics,
     HeapObjectHeader* header, size_t object_size) {
   if (!NameProvider::HideInternalNames()) {
@@ -109,7 +109,7 @@ HeapStatistics HeapStatisticsCollector::CollectDetailedStatistics(
   if (!NameProvider::HideInternalNames()) {
     stats.type_names.resize(type_name_to_index_map_.size());
     for (auto& it : type_name_to_index_map_) {
-      stats.type_names[it.second] = it.first;
+      stats.type_names[it.second] = reinterpret_cast<const char*>(it.first);
     }
   }
 

src/heap/cppgc/heap-statistics-collector.h

@@ -30,10 +30,10 @@ class HeapStatisticsCollector : private HeapVisitor<HeapStatisticsCollector> {
   HeapStatistics::SpaceStatistics* current_space_stats_ = nullptr;
   HeapStatistics::PageStatistics* current_page_stats_ = nullptr;
   // Index from type name to final index in `HeapStats::type_names`.
-  // Canonicalizing based on `const char*` assuming stable addresses. If the
+  // Canonicalizing based on `const void*` assuming stable addresses. If the
   // implementation of `NameProvider` decides to return different type name
   // c-strings, the final outcome is less compact.
-  std::unordered_map<const char*, size_t> type_name_to_index_map_;
+  std::unordered_map<const void*, size_t> type_name_to_index_map_;
 };
 
 }  // namespace internal