Add flip to tensor (#2855)

* Add `flip` to `tensor`

* Move the tests to the proper places.

---------

Co-authored-by: laurent <laurent.mazare@gmail.com>

candle-core/src/test_utils.rs

@@ -24,6 +24,15 @@ macro_rules! test_device {
     };
 }
 
+pub fn assert_tensor_eq(t1: &Tensor, t2: &Tensor) -> Result<()> {
+    assert_eq!(t1.shape(), t2.shape());
+    // Default U8 may not be large enough to hold the sum (`t.sum_all` defaults to the dtype of `t`)
+    let eq_tensor = t1.eq(t2)?.to_dtype(crate::DType::U32)?;
+    let all_equal = eq_tensor.sum_all()?;
+    assert_eq!(all_equal.to_scalar::<u32>()?, eq_tensor.elem_count() as u32);
+    Ok(())
+}
+
 pub fn to_vec0_round(t: &Tensor, digits: i32) -> Result<f32> {
     let b = 10f32.powi(digits);
     let t = t.to_vec0::<f32>()?;