[lldb] Remove FileSpec(FileSpec*) constructor

This constructor was the cause of some pretty weird behavior. Remove it,
and update all code to properly dereference the argument instead.

lldb/source/API/SBThread.cpp

@@ -1037,7 +1037,7 @@ SBError SBThread::JumpToLine(lldb::SBFileSpec &file_spec, uint32_t line) {
 
   Thread *thread = exe_ctx.GetThreadPtr();
 
-  Status err = thread->JumpToLine(file_spec.get(), line, true);
+  Status err = thread->JumpToLine(file_spec.ref(), line, true);
   sb_error.SetError(err);
   return LLDB_RECORD_RESULT(sb_error);
 }