Disable hidden visibility for mex
Disable hidden visibility for mex

Our mex code has problems turning on hidden visibility. While we really
should fix this eventually (we'll have to if we are ever to move away
from mex.cmake to using the upstream mex support from FindMatlab.cmake),
it's non-trivial, so just work around it for now.

sheim/drake,sheim/drake,billhoffman/drake,billhoffman/drake,sheim/drake,billhoffman/drake,sheim/drake,billhoffman/drake,sheim/drake,billhoffman/drake,sheim/drake,billhoffman/drake,billhoffman/drake,billhoffman/drake,sheim/drake,sheim/drake