Libc++ frequently creates and uses utilities written in python.
Currently there are python modules under both libcxx/test and
libcxx/util. My goal with these changes is to consolidate them
into a single package under libcxx/utils/libcxx.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@294644 91177308-0d34-0410-b5e6-96231b3b80d8
