[Buildroot] Python: ctype: find_library support

[Yegor Yefremov]

This subject was brought up yesterday on IRC.

Some packages like pyudev
(https://pyudev.readthedocs.org/en/latest/index.html) require
find_library support in order to emit proper *.so name. To do so,
Python uses either /sbin/ldconfig, objdump or gcc (see
https://docs.python.org/2/library/ctypes.html#finding-shared-libraries).
See build/python-2.7.9/Lib/ctypes/util.py for implementation details.

As we don't supply target gcc and objdump, /sbin/ldconfig seems to be
the only solution. But in the default configuration of internally
built toolchain library cache is disabled and in external toolchains
(Sourcery CodeBench ARM 2014.05 for example), ldconfig is not provided
at all.

How can we solve this issue?

Yegor