FTBFS with altivec on ppc64el

cannot reproduce with cross-compiler.

[ 80%] Generating opencv_ocl_pch_dephelp.cxx
cd /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl && /usr/bin/cmake -E echo \#include\ \"/build/buildd/opencv-2.4.6.1+dfsg/modules/ocl/src/precomp.hpp\" > /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl/opencv_ocl_pch_dephelp.cxx
cd /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl && /usr/bin/cmake -E echo int\ testfunction\(\)\; >> /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl/opencv_ocl_pch_dephelp.cxx
cd /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl && /usr/bin/cmake -E echo int\ testfunction\(\) >> /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl/opencv_ocl_pch_dephelp.cxx
cd /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl && /usr/bin/cmake -E echo { >> /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl/opencv_ocl_pch_dephelp.cxx
cd /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl && /usr/bin/cmake -E echo \ \ \ \ \return\ 0\; >> /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl/opencv_ocl_pch_dephelp.cxx
cd /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl && /usr/bin/cmake -E echo } >> /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl/opencv_ocl_pch_dephelp.cxx
cd /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /build/buildd/opencv-2.4.6.1+dfsg /build/buildd/opencv-2.4.6.1+dfsg/modules/ocl /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl/CMakeFiles/opencv_ocl_pch_dephelp.dir/DependInfo.cmake --color=
Scanning dependencies of target opencv_ocl_pch_dephelp
make[3]: Leaving directory `/build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu'
make -f modules/ocl/CMakeFiles/opencv_ocl_pch_dephelp.dir/build.make modules/ocl/CMakeFiles/opencv_ocl_pch_dephelp.dir/build
make[3]: Entering directory `/build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu'
/usr/bin/cmake -E cmake_progress_report /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/CMakeFiles
[ 80%] Building CXX object modules/ocl/CMakeFiles/opencv_ocl_pch_dephelp.dir/opencv_ocl_pch_dephelp.cxx.o
cd /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl && /usr/bin/c++ -DCVAPI_EXPORTS -DHAVE_CVCONFIG_H -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2 -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -Wno-shadow -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -DNDEBUG -isystem /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu -isystem /usr/include/eigen3 -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/ocl/include -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/ocl/src -isystem /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/core/include -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/imgproc/include -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/flann/include -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/highgui/include -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/features2d/include -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/objdetect/include -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/video/include -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/calib3d/include -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/ts/include -isystem /build/buildd/opencv-2.4.6.1+dfsg/modules/ocl/perf -o CMakeFiles/opencv_ocl_pch_dephelp.dir/opencv_ocl_pch_dephelp.cxx.o -c /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl/opencv_ocl_pch_dephelp.cxx
In file included from /usr/include/CL/cl.h:30:0,
                 from /usr/include/CL/opencl.h:42,
                 from /build/buildd/opencv-2.4.6.1+dfsg/modules/ocl/include/opencv2/ocl/private/util.hpp:54,
                 from /build/buildd/opencv-2.4.6.1+dfsg/modules/ocl/src/precomp.hpp:82,
                 from /build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu/modules/ocl/opencv_ocl_pch_dephelp.cxx:1:
/usr/include/CL/cl_platform.h:335:12: error: 'vector' does not name a type
    typedef vector unsigned char __cl_uchar16;
            ^
/usr/include/CL/cl_platform.h:336:12: error: 'vector' does not name a type
    typedef vector signed char __cl_char16;
            ^
/usr/include/CL/cl_platform.h:337:12: error: 'vector' does not name a type
    typedef vector unsigned short __cl_ushort8;
            ^
/usr/include/CL/cl_platform.h:338:12: error: 'vector' does not name a type
    typedef vector signed short __cl_short8;
            ^
/usr/include/CL/cl_platform.h:339:12: error: 'vector' does not name a type
    typedef vector unsigned int __cl_uint4;
            ^
/usr/include/CL/cl_platform.h:340:12: error: 'vector' does not name a type
    typedef vector signed int __cl_int4;
            ^
/usr/include/CL/cl_platform.h:341:12: error: 'vector' does not name a type
    typedef vector float __cl_float4;
            ^
/usr/include/CL/cl_platform.h:548:5: error: '__cl_char16' does not name a type
     __cl_char16 v16;
     ^
/usr/include/CL/cl_platform.h:623:5: error: '__cl_uchar16' does not name a type
     __cl_uchar16 v16;
     ^
/usr/include/CL/cl_platform.h:676:5: error: '__cl_short8' does not name a type
     __cl_short8 v8;
     ^
/usr/include/CL/cl_platform.h:695:5: error: '__cl_short8' does not name a type
     __cl_short8 v8[2];
     ^
/usr/include/CL/cl_platform.h:751:5: error: '__cl_ushort8' does not name a type
     __cl_ushort8 v8;
     ^
/usr/include/CL/cl_platform.h:770:5: error: '__cl_ushort8' does not name a type
     __cl_ushort8 v8[2];
     ^
/usr/include/CL/cl_platform.h:803:5: error: '__cl_int4' does not name a type
     __cl_int4 v4;
     ^
/usr/include/CL/cl_platform.h:822:5: error: '__cl_int4' does not name a type
     __cl_int4 v4[2];
     ^
/usr/include/CL/cl_platform.h:841:5: error: '__cl_int4' does not name a type
     __cl_int4 v4[4];
     ^
/usr/include/CL/cl_platform.h:878:5: error: '__cl_uint4' does not name a type
     __cl_uint4 v4;
     ^
/usr/include/CL/cl_platform.h:897:5: error: '__cl_uint4' does not name a type
     __cl_uint4 v4[2];
     ^
/usr/include/CL/cl_platform.h:916:5: error: '__cl_uint4' does not name a type
     __cl_uint4 v4[4];
     ^
/usr/include/CL/cl_platform.h:1103:5: error: '__cl_float4' does not name a type
     __cl_float4 v4;
     ^
/usr/include/CL/cl_platform.h:1122:5: error: '__cl_float4' does not name a type
     __cl_float4 v4[2];
     ^
/usr/include/CL/cl_platform.h:1141:5: error: '__cl_float4' does not name a type
     __cl_float4 v4[4];
     ^
make[3]: *** [modules/ocl/CMakeFiles/opencv_ocl_pch_dephelp.dir/opencv_ocl_pch_dephelp.cxx.o] Error 1
make[3]: Leaving directory `/build/buildd/opencv-2.4.6.1+dfsg/obj-powerpc64le-linux-gnu'
make[2]: *** [modules/ocl/CMakeFiles/opencv_ocl_pch_dephelp.dir/all] Error 2