Fix linking of lldb-server with BUILD_SHARED_LIBS

Summary:
The BUILD_SHARED_LIBS branch of lldb-server link flags was hopelessly broken, at least since we
started restricting the symbols exported by liblldb. lldb-server depends on symbols from the
lldb_private namespace, so it cannot link to the public interface of liblldb. Instead I make it
link to the individual libraries constituting liblldb, just like it does in the
!BUILD_SHARED_LIBS case.

This does not make the BUILD_SHARED_LIBS build of lldb fully functional yet, due to the way
liblldb dependencies are managed, but it's a step in that direction.

Reviewers: zturner, tfiala

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D16678

llvm-svn: 259188