Remove #include, for we don't need the definitions of these classes.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@189713 91177308-0d34-0410-b5e6-96231b3b80d8
Fix build breakage

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@189714 91177308-0d34-0410-b5e6-96231b3b80d8