Fix most GCC attribute ignored warnings

llvm-svn: 267074
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 89dd1dd2782de71d56c512e44b9dfda2f7b95351
diff --git a/include/bitset b/include/bitset
index 87d7afc..3f9b964 100644
--- a/include/bitset
+++ b/include/bitset
@@ -656,7 +656,7 @@
 }
 
 template <size_t _Size> class _LIBCPP_TYPE_VIS_ONLY bitset;
-template <size_t _Size> struct _LIBCPP_TYPE_VIS_ONLY hash<bitset<_Size> >;
+template <size_t _Size> struct hash<bitset<_Size> >;
 
 template <size_t _Size>
 class _LIBCPP_TYPE_VIS_ONLY bitset