sim: ppc: unify igen line number output modules

sim: ppc: unify igen line number output modules

The common igen code was forked from the ppc long ago.  The lf module
is still pretty similar in API, so we can unfork them with a little
bit of effort.

Some of the generated ppc code is now slightly different, but that's
because of fixes the common igen code has gained, but not the ppc igen
code (e.g. fixing of #line numbers).

The ppc code retains lf_print__c_code because the common igen code
rewrote the logic to a new table.c API.  Let's delay that in the ppc
code to at least unfork all this code.