fix float16

Author: NKNaN

python/paddle/tensor/math.py

@@ -7678,7 +7678,8 @@ def sinc(x, name=None):
  if not isinstance(x, (paddle.Tensor, Variable, paddle.pir.Value)):
  raise TypeError(f"x must be tensor type, but got {type(x)}")
 
- tmp = math.pi * paddle.where(x == 0, 1.0e-20, x)
+ tmp = paddle.where(x != 0, x, paddle.full_like(x, 1.0e-20))
+ tmp = paddle.multiply(tmp, paddle.to_tensor(math.pi, dtype=x.dtype))
  return paddle.divide(tmp.sin(), tmp)