[PATCH] Add Position-independent Code model Module API.

[Rafael Espíndola]

> ----------------
> rafael wrote:
>> Why XFAIL?
> This test is intended to fail (test merging two different values for !flag_pic).  Is there a better way to do this?

Yes, use the not utility (RUN: not llvm-link...). It is probably a
good idea to FileCheck for whatever error message we print.

Cheers,
Rafael