wangone issues

Results 7 issues of


                                            wangone

test x86 meta_op_test

https://github.com/PaddlePaddle/CINN/pull/429

https://github.com/PaddlePaddle/CINN/pull/417 computeAt lowered ir is different with computeAt2 lowered ir

schedule分别设置computeAt和computeAt2, default case生成的ir不同 @haozech

isl for1 wrong elimination after splitting 执行test02_matmul_case i_outer和j_outer是for1，isl错误消除，导致最后一个轴vectorize根据level找不到for轴

enhancement