On Wed, 11 Nov 2015, Jonathan Wakely wrote:
> Fixed by this patch.

Thanks, Jonathan!  Unfortunately bootstrap is still broken
(on i386-unknown-freebsd11.0 at least):

In file included from 
/scratch/tmp/gerald/gcc-HEAD/libstdc++-v3/src/c++11/thread.cc:27:0:
/scratch/tmp/gerald/OBJ-1112-1414/i386-unknown-freebsd10.2/libstdc++-v3/include/
thread: In function ‘void std::this_thread::sleep_for(const std::chrono::duration<_Rep1, _Period1>&)’:
/scratch/tmp/gerald/OBJ-1112-1414/i386-unknown-freebsd10.2/libstdc++-v3/include/
thread:300:44: error: ‘errno’ was not declared in this scope
  while (::nanosleep(&__ts, &__ts) == -1 && errno == EINTR)
                                            ^
/scratch/tmp/gerald/OBJ-1112-1414/i386-unknown-freebsd10.2/libstdc++-v3/include/
thread:300:53: error: ‘EINTR’ was not declared in this scope
  while (::nanosleep(&__ts, &__ts) == -1 && errno == EINTR)

Gerald