[llvm] [GSYM] Callsites: Add data format support and loading from YAML (PR #109781)

[Kyungwoo Lee via llvm-commits]

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@@ -385,6 +385,12 @@ uint32_t GsymCreator::insertString(StringRef S, bool Copy) {
   return StrOff;
 }
 
+StringRef GsymCreator::getString(uint32_t offset) {
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kyulee-com wrote:

Can we return an optional value like std::optional<StringRef>? The release build ignores asserts. I'd make it explicit for its use.

https://github.com/llvm/llvm-project/pull/109781