GCC libraries are sometimes built with -fPIC, sometimes not

[boegel]

It seems like the GCC libraries (e.g. libiberty.a) sometimes end up being built with -fPIC (e.g. on SL5), and sometimes not (e.g. on SL6), while eb is performing the exact same build procedure.

This causes problems for cairo (see ) and ExtraE (part of UNITE), which require libiberty.a to be built with -fPIC. The cairo builds works fine on SL5, but doesn't work on SL6 (see also easybuilders/easybuild-easyconfigs#494 (comment)).