Documentation: add a note that Clang on Mageia 2 can not find libstdc++ headers


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171729 91177308-0d34-0410-b5e6-96231b3b80d8
Make the MergeGlobals pass correctly handle the address space qualifiers of the global variables. We partition the set of globals by their address space, and apply the same the trasnformation as before to merge them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171730 91177308-0d34-0410-b5e6-96231b3b80d8