On Linux the NAG Fortran compiler uses gcc under the hood to link.  Use
"-Wl,-v" to pass "-v" to the underlying gcc compiler to get verbose link
output.  Detect the NAG Fortran directory (using -dryrun) and then honor
object files in the directory referenced in the implicit link line.
Pass real linker options with "-Wl,-Xlinker,".  The -Wl, gets through
the NAG front-end and the -Xlinker gets through the gcc front-end.