Updating CMake to the latest stable version as done in the previous
commit solves the reproducibility issue only partly. We need to patch
the code that merges libc++abi.a into libc++.a to get the order in the
merged archive deterministic. The code doing the merging is:

`files = glob.glob(os.path.join(temp_directory_root, '*.o*'))`

Regarding `glob` there is following in the Python docs:

"The glob module finds all the pathnames matching a specified pattern
 according to the rules used by the Unix shell, although results are
 returned in *arbitrary* order." (emphasis mine)

(https://docs.python.org/2/library/glob.html)