[PATCH] Forward to correct function in std::shared_mutex::unlock().

This commits the patch from https://gcc.gnu.org/ml/gcc-patches/2015-08/msg00663.html and adds tests for all the mutex types. Eelis, thanks for the patch. Please CC the libstdc++ list for all libstdc++ patches, I don't subscribe to gcc-patches and only saw your mail because Ville brought it to my

[PATCH] Forward to correct function in std::shared_mutex::unlock().

Looks like a typo. :) Index: libstdc++-v3/include/std/shared_mutex === --- libstdc++-v3/include/std/shared_mutex (revision 226840) +++ libstdc++-v3/include/std/shared_mutex (working copy) @@ -331,7 +331,7 @@ void lock() { _M_im