Function gfor

test/approx1.cpp:383–386

    array outGFOR(pos.dims());
    gfor(seq i, pos.dims(1)) {
        outGFOR(span, i) =
            approx1(input(span, i), pos(span, i), AF_INTERP_NEAREST);
    }

    ASSERT_NEAR(0, sum<float>(abs(outBatch - outSerial)), 1e-3);
    ASSERT_NEAR(0, sum<float>(abs(outBatch - outGFOR)), 1e-3);