Implement move constructor and remove copy constructor for Filter objects in FixedLenDecoderEmitter. Also remove unused copy constructor of FilterChooser.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217013 91177308-0d34-0410-b5e6-96231b3b80d8
Use unique_ptr to manager FilterChooser ownership.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217014 91177308-0d34-0410-b5e6-96231b3b80d8