[llvm] [FileCheck] Remove unneeded unique_ptr. NFC. (PR #123216)

[Jay Foad via llvm-commits]

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@@ -180,8 +180,7 @@ struct FileCheckString;
 class FileCheck {
   FileCheckRequest Req;
   std::unique_ptr<FileCheckPatternContext> PatternContext;
-  // C++17 TODO: make this a plain std::vector.
-  std::unique_ptr<std::vector<FileCheckString>> CheckStrings;
+  std::vector<FileCheckString> CheckStrings;
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jayfoad wrote:

I don't even understand why this was required pre-C++17. Everything seems to work when I remove it.

https://github.com/llvm/llvm-project/pull/123216