[clang] [clang] Do not share ownership of `HeaderSearchOptions` (PR #132984)

[Ben Langmuir via cfe-commits]

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@@ -116,7 +116,7 @@ class ASTUnit {
   std::shared_ptr<Preprocessor>           PP;
   IntrusiveRefCntPtr<ASTContext>          Ctx;
   std::shared_ptr<TargetOptions>          TargetOpts;
-  std::shared_ptr<HeaderSearchOptions>    HSOpts;
+  std::unique_ptr<HeaderSearchOptions> HSOpts;
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benlangmuir wrote:

Is there still a reason to keep this a pointer?

https://github.com/llvm/llvm-project/pull/132984