message: remove ispc symbol defs that no longer exist
diff: @@ -5,14 +5,9 @@ Distribution2D_sample___un_3C_s_5B__c_unDistribution2D_5D__3E_REFs_5B__c_vyvec2f
  FrameBuffer_Constructor___un_3C_s_5B_unFrameBuffer_5D__3E_un_3C_unv_3E_,
  FrameBuffer_set___un_3C_s_5B_unFrameBuffer_5D__3E_CunuCunuuni,
  Geometry_Constructor___un_3C_s_5B_unGeometry_5D__3E_un_3C_unv_3E_un_3C____un_3C_s_5B__c_unGeometry_5D__3E_REFs_5B_vyDifferentialGeometry_5D_REFs_5B__c_vyRay_5D_unI_3E_,
  -GridAccelerator_createInstance___un_3C_unv_3E_,
  -GridAccelerator_destroy___un_3C_s_5B_unGridAccelerator_5D__3E_,
  -GridAccelerator_intersectIsosurface___un_3C_s_5B_unGridAccelerator_5D__3E_unfun_3C_unf_3E_uniREFs_5B_vyRay_5D_,
  Light_eval___un_3C_s_5B__c_unLight_5D__3E_REFs_5B__c_vyDifferentialGeometry_5D_REFs_5B__c_vyvec3f_5D_CvyfCvyf,
  Renderer_Constructor___un_3C_s_5B_unRenderer_5D__3E_un_3C_unv_3E_,
  Renderer_Constructor___un_3C_s_5B_unRenderer_5D__3E_un_3C_unv_3E_Cuni,
  -SharedStructuredVolume_Constructor___un_3C_s_5B_unSharedStructuredVolume_5D__3E_un_3C_unv_3E_CuniREFs_5B__c_unvec3i_5D_un_3C_Cunv_3E_,
  -StructuredVolume_Constructor___un_3C_s_5B_unStructuredVolume_5D__3E_un_3C_unv_3E_REFs_5B__c_unvec3i_5D_,
  Volume_Constructor___un_3C_s_5B_unVolume_5D__3E_un_3C_unv_3E_,
  delete_uniform___un_3C_unv_3E_,
  delete_uniform_,
  