This patch places class definitions in implementation files into anonymous
namespaces to prevent weak vtables. This eliminates the need of providing an
out-of-line definition to pin the vtable explicitly to the file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195092 91177308-0d34-0410-b5e6-96231b3b80d8