Make sure LLVMLoadLibraryPermanently gets an extern "C" symbol.

Otherwise it's impossible to use it. Also don't include C++ headers in
a C header.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194581 91177308-0d34-0410-b5e6-96231b3b80d8
Move Delinearization pass into an anonymous namespace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194582 91177308-0d34-0410-b5e6-96231b3b80d8