Mount the devpts file system.

The lack of a devpts file system was causing mysterious GNU Binutils
test suite failures, with these "spawn failed" errors in the test log:

    Test Run By root on Sun Dec  8 20:36:45 2013
    Native configuration is x86_64-unknown-linux-gnu

                    === binutils tests ===

    Schedule of variations:
        unix

    Running target unix
    Using /usr/share/dejagnu/baseboards/unix.exp as board description file for target.
    Using /usr/share/dejagnu/config/unix.exp as generic interface file for target.
    Using /usr/src/binutils_2.23.2-1/tmp/src/binutils/testsuite/config/default.exp as tool-and-target-specific interface file.
    Running /usr/src/binutils_2.23.2-1/tmp/src/binutils/testsuite/binutils-all/ar.exp ...
    /usr/src/binutils_2.23.2-1/tmp/build-core-linux-eglibc/binutils/ar rc tmpdir/artest.a tmpdir/abcdefghijklmnopqrstuvwxyz1 tmpdir/abcdefghijklmnopqrstuvwxyz2
    Executing on host: /usr/src/binutils_2.23.2-1/tmp/build-core-linux-eglibc/binutils/ar rc tmpdir/artest.a tmpdir/abcdefghijklmnopqrstuvwxyz1 tmpdir/abcdefghijklmnopqrstu
    vwxyz2   (timeout = 300)
    spawn /usr/src/binutils_2.23.2-1/tmp/build-core-linux-eglibc/binutils/ar rc tmpdir/artest.a tmpdir/abcdefghijklmnopqrstuvwxyz1 tmpdir/abcdefghijklmnopqrstuvwxyz2M
    spawn failed
    [...]

                    === binutils Summary ===

    # of unexpected failures        6
    # of unresolved testcases       48
    # of untested testcases         7
    # of unsupported tests          4
    runtest completed at Sun Dec  8 20:36:45 2013

After spelunking through Binutils and DejaGnu code (exploring the great
remote_exec and local_exec procedures of DejaGnu), I tried the
following, which resulted in much more helpful information:

    $ expect
    expect1.1> spawn echo hello
    spawn echo hello
    The system has no more ptys.  Ask your system administrator to create more.
        while executing
    "spawn echo hello"

0 files changed, 0 insertions, 0 deletions