[CMake] llvm-shlib: Add possibly missing BitReader and MCDisassembler for llvm-c.

FYI, 3 modules below are redundant in trunk;

  AsmPrinter
  MC
  SelectionDAG

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221579 91177308-0d34-0410-b5e6-96231b3b80d8