LCC: link with -lgfortran instead of -llfortran since 1.26.03

Since LCC 1.26.03, compiler developers decided to rename
liblfortran to libgfortran (internal reference: mcstbug#131633),
and despite it's stated that "-llfortran will be automatically
treated as -lgfortran", it actually does not work (and there's
even no symlinks like liblfortran.* -> libgfortran.*); so we
have to explicitly choose which library we have to link in.

Fixes: #23646