Revert r200560, "LTO itself hasn't depended on MCDisassembler any more."

Oh sorry, I missed LTO.exports, ... I checked just only *.cpp(s).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200562 91177308-0d34-0410-b5e6-96231b3b80d8