* misc/error.c (error): Handle wide oriented stderr stream correctly.
* stdio-common/perror.c (perror): Implement according to standard.
The stream orientation must not be changed if the stream was not
oriented before the call.
* stdio-common/Makefile (tests): Add tst-perror.
* stdio-common/tst-perror.c: New file.
See ChangeLog.12 for earlier changes.