libstdc++: Fix std::filesystem build failure for Windows

The std::filesystem code needs to use posix::DIR not ::DIR, as that is
an alias for _WDIR on Windows.

libstdc++-v3/ChangeLog:

	* src/filesystem/dir-common.h (_Dir_base::openat): Change return
	type to use portable posix::DIR alias.

(cherry picked from commit 6e3419529d4e3284172f9965b4993b9f184f34d2)

diff --git a/libstdc++-v3/src/filesystem/dir-common.h b/libstdc++-v3/src/filesystem/dir-common.h
index 33892c49bf28f986a86593367ae6145d47b5a72a..bc7348817827bde0701370840ce7b60232410c2a 100644 (file)
--- a/libstdc++-v3/src/filesystem/dir-common.h
+++ b/libstdc++-v3/src/filesystem/dir-common.h
@@ -173,7 +173,7 @@ struct _Dir_base
     return true;
   }
 
-  static ::DIR*
+  static posix::DIR*
   openat(int fd, const posix::char_type* pathname, bool nofollow)
   {
 #if _GLIBCXX_HAVE_FDOPENDIR && defined O_RDONLY && defined O_DIRECTORY \