[llvm] [BOLT] Use symbol table info in registerFragment (PR #89648)

[Amir Ayupov via llvm-commits]

================
@@ -28,6 +28,13 @@ class NameResolver {
   static constexpr char Sep = '/';
 
 public:
+  /// Return the number of duplicates registered for a given \p Name.
----------------
aaupov wrote:

Let me rename/rephrase it to "counter" instead to make it more clear.
I took "duplicates" from the comment above.

https://github.com/llvm/llvm-project/pull/89648