解决empty算子问题；增加ULP比对逻辑用于矩阵乘法（包括linear算子）

[jianzhang96]

1.run_ut.py中添加算子白名单，跳过empty算子。
2.更新compare比对算法，增加了ULP误差比对，其主要用于矩阵乘法，linear算子也包括，其中使用矩阵乘法。ULP比对主要用于三方比对api_precision_compare.py。

什么是ULP (unit in the last place)？CSDN
ULP比对标准：att仓库

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