Handle file position information for fragments differently: Instead of

Handle file position information for fragments differently: Instead of
handling them separately (which has historic reasons), generate real line info
information. This means that line info for the assembler source will be part
of the debug info file.

git-svn-id: svn://svn.cc65.org/cc65/trunk@4774 b7a2c559-68d2-44c3-8de9-860c34a00d81