Merging r343369:

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r343369 | vitalybuka | 2018-09-28 19:17:12 -0700 (Fri, 28 Sep 2018) | 1 line

[cxx2a] Fix warning triggered by r343285
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llvm-svn: 348453

Author: tstellar

libcxx/src/filesystem/operations.cpp

@@ -352,7 +352,6 @@ struct FileDescriptor {
 
   ~FileDescriptor() { close(); }
 
-  FileDescriptor() = default;
   FileDescriptor(FileDescriptor const&) = delete;
   FileDescriptor& operator=(FileDescriptor const&) = delete;