flex: Break the hardlinks to fix quickworld issues.

flex: Break the hardlinks to fix quickworld issues.

Upon repeated quickworld run when install -C installs the libfl.a it breaks
the previous hardlink and retrigers relink for anything that depends on -ll.

Solve this by changing logic to install compat libs for install target only.
During buildworld only main ${LIBL} should be used where needed.

Fix a single case where -lfl was used in binutils. Add missing DPADD too.