ns build symlinks all libexec programs into bin directory

[Glenn Morris]

Why does a --with-ns build do this (in install-arch-dep):

cd nextstep/Emacs.app/bin
ls -l
    hexl -> ../libexec/hexl
    movemail -> ../libexec/movemail
    profile -> ../libexec/profile
    rcs2log -> ../libexec/rcs2log
    update-game-score -> ../libexec/update-game-score
    vcdiff -> ../libexec/vcdiff

Ie, create symlinks to the libexec programs in the bin directory?

These programs are supposed to be for internal Emacs use only, which is
why they get installed in libexec in the first place.