$ emerge -pv --depclean $(for x in $(portageq match / 'app-emulation/emul-linux-x86-*') ; do echo =$x ; done)

Calculating dependencies... done!
  app-emulation/emul-linux-x86-baselibs-20140508-r12 pulled in by:
    app-emulation/emul-linux-x86-gtklibs-20140508-r3 requires ~app-emulation/emul-linux-x86-baselibs-20140508
    app-emulation/wine-1.6.2 requires app-emulation/emul-linux-x86-baselibs, >=app-emulation/emul-linux-x86-baselibs-20130224[development], app-emulation/emul-linux-x86-baselibs[development]
    x11-libs/libSM-1.2.2 requires app-emulation/emul-linux-x86-baselibs[development]

  app-emulation/emul-linux-x86-gstplugins-20140508-r1 pulled in by:
    app-emulation/wine-1.6.2 requires app-emulation/emul-linux-x86-gstplugins

  app-emulation/emul-linux-x86-gtklibs-20140508-r3 pulled in by:
    sys-devel/gcc-4.8.3 requires app-emulation/emul-linux-x86-gtklibs

  app-emulation/emul-linux-x86-medialibs-20140508-r6 pulled in by:
    app-emulation/wine-1.6.2 requires app-emulation/emul-linux-x86-medialibs[development]

  app-emulation/emul-linux-x86-opengl-20140508 pulled in by:
    app-emulation/emul-linux-x86-gtklibs-20140508-r3 requires ~app-emulation/emul-linux-x86-opengl-20140508
    app-emulation/wine-1.6.2 requires app-emulation/emul-linux-x86-opengl[development]

  app-emulation/emul-linux-x86-xlibs-20140508 pulled in by:
    app-emulation/emul-linux-x86-gtklibs-20140508-r3 requires ~app-emulation/emul-linux-x86-xlibs-20140508
    app-emulation/wine-1.6.2 requires >=app-emulation/emul-linux-x86-xlibs-2.1[development], app-emulation/emul-linux-x86-xlibs[development]
    media-gfx/nvidia-cg-toolkit-3.1.0013-r2 requires app-emulation/emul-linux-x86-xlibs
    sys-devel/gcc-4.8.3 requires app-emulation/emul-linux-x86-xlibs

>>> No packages selected for removal by depclean
Packages installed:   2230
Packages in world:    667
Packages in system:   44
Required packages:    2230
Number to remove:     0