it's bound to the bourne shell, which is not readily available on
windows hosts.
on the way, the pch, fvisibility, and bsymbolic_functions tests were
rewritten as regular compile tests. they now just verify that qmake's
built-in support for the tested features actually works.
Change-Id: Ibac246f21b5ececa40da3f576dc789982eaf9fdf
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
