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

[James Henderson 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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jh7370 wrote:

IIRC, prior to C++17, possibly even prior C++14, with at least some compilers (I ran into this with GCC, I believe, but not MSVC), you couldn't have vectors of incomplete types, so that would be why.

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