Allow attempts to build with other than visstudio 2013
The ispc check was too early, before the ispc enable state was known. As a result, the superbuild would not let the user try to use anything other than visstudio 2013.
The ispc check was too early, before the ispc enable state was known. As a result, the superbuild would not let the user try to use anything other than visstudio 2013.