Michael van der Westhuizen: update to CMake.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@174731 91177308-0d34-0410-b5e6-96231b3b80d8
Add Michael van der Westhuizen to CREDITS.TXT

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@174732 91177308-0d34-0410-b5e6-96231b3b80d8
Michael van der Westhuizen: Update instructions for building on Linux.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@174733 91177308-0d34-0410-b5e6-96231b3b80d8