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

[Maksim Panchenko via llvm-commits]

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

When the function returns `1`, does it mean it has a duplicate?

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