[llvm] [SampleProfile] Support MD5-based ProfileSymbolList (PR #210235)

[David Li via llvm-commits]

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@@ -1688,19 +1696,45 @@ class ProfileSymbolList {
     Syms.insert(Name.copy(Allocator));
   }
 
-  bool contains(StringRef Name) { return Syms.count(Name); }
+  bool contains(StringRef Name) const {
+    return Syms.count(Name) || ColdGUIDTable.contains(llvm::MD5Hash(Name));
+  }
 
   void merge(const ProfileSymbolList &List) {
+    assert(List.ColdGUIDTable.empty() &&
+           "Merging pre-hashed MD5 ProfileSymbolList not yet implemented");
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david-xl wrote:

is this an essencial opration?

https://github.com/llvm/llvm-project/pull/210235