Fix handling of temporary files.

2012-05-05  Janne Blomqvist  <jb@gcc.gnu.org>

        * gfortran.texi (GFORTRAN_TMPDIR): Rename to TMPDIR, explain
        algorithm for choosing temp directory.


2012-05-05  Janne Blomqvist  <jb@gcc.gnu.org>

        * config.h.in: Regenerated.
        * configure: Regenerated.
        * configure.ac: Add checks for getegid and __secure_getenv.
        * io/unix.c (P_tmpdir): Fallback definition for macro.
        (tempfile_open): New function.
        (tempfile): Use secure_getenv, call tempfile_open to try each
        directory in turn.
        * libgfortran.h (DEFAULT_TMPDIR): Remove macro.
        (secure_getenv): New macro/prototype.
        * runtime/environ.c (secure_getenv): New function.
        (variable_table): Rename GFORTRAN_TMPDIR to TMPDIR.
        * runtime/main.c (find_addr2line): Use secure_getenv.

From-SVN: r187190