Make anonymous namespace as small as possible.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@199021 91177308-0d34-0410-b5e6-96231b3b80d8
[PECOFF] Support VERSION directive.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@199022 91177308-0d34-0410-b5e6-96231b3b80d8