Fix linking of lldb-server with BUILD_SHARED_LIBS

[labath]

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.

[tfiala]

Seems reasonable to me.

tools/lldb-server/CMakeLists.txt

 add_lldb_executable(lldb-server
     Acceptor.cpp
     lldb-gdbserver.cpp
     lldb-platform.cpp
     lldb-server.cpp
     LLDBServerUtilities.cpp
 )
 
-if (BUILD_SHARED_LIBS )
-  target_link_libraries(lldb-server liblldb)
-  target_link_libraries(lldb-server ${LLDB_SYSTEM_LIBS})
-else()
-  # The Darwin linker doesn't understand --start-group/--end-group.
-  if (LLDB_LINKER_SUPPORTS_GROUPS)
-    target_link_libraries(lldb-server
-                          -Wl,--start-group ${LLDB_USED_LIBS} -Wl,--end-group)
-    target_link_libraries(lldb-server
-                          -Wl,--start-group ${CLANG_USED_LIBS} -Wl,--end-group)
-  else()
-    target_link_libraries(lldb-server ${LLDB_USED_LIBS})
-    target_link_libraries(lldb-server ${CLANG_USED_LIBS})
-  endif()
-  llvm_config(lldb-server ${LLVM_LINK_COMPONENTS})
 
-  target_link_libraries(lldb-server ${LLDB_SYSTEM_LIBS})
-endif()
 
 set_target_properties(lldb-server PROPERTIES VERSION ${LLDB_VERSION})
 
 install(TARGETS lldb-server
   RUNTIME DESTINATION bin)