!12031 Add shape check to Dense

From: @wanyiming
Reviewed-by: @zh_qh,@kingxian
Signed-off-by: @kingxian

mindspore/nn/layer/basic.py

@@ -202,6 +202,12 @@ class Flatten(Cell):
     def construct(self, x):
         return F.reshape(x, (F.shape(x)[0], -1))
 
+@constexpr
+def check_dense_input_shape(x):
+    if len(x) < 2:
+        raise ValueError('For Dense, the dimension of input should not be less than 2, while the input dimension is '
+                         + f'{len(x)}.')
+
 class Dense(Cell):
     r"""
     The dense connected layer.
@@ -291,6 +297,7 @@ class Dense(Cell):
 
     def construct(self, x):
         x_shape = self.shape_op(x)
+        check_dense_input_shape(x_shape)
         if len(x_shape) != 2:
             x = self.reshape(x, (-1, x_shape[-1]))
         x = self.matmul(x, self.weight)