include/
        * libiberty.h (PEX_STDERR_TO_PIPE): New define.
        (PEX_BINARY_ERROR): New define.
        (pex_read_err): New function.

        libiberty/
        * pex-common.h (struct pex_obj): New fields
        stderr_pipe and read_err.
        * pex-common.c (pex_init_common): Initialize
        stderr_pipe.

From-SVN: r121430