[PECOFF] Make a member functions non-virtual.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@197006 91177308-0d34-0410-b5e6-96231b3b80d8
Use "static" instead of anonymous namespace.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@197007 91177308-0d34-0410-b5e6-96231b3b80d8