[X86] Optimization of inserting vxi1 sub vector into vXi1 vector

[X86] Optimization of inserting vxi1 sub vector into vXi1 vector

Summary:
After bugfix the undef value case here, we used more operations to implement inserting vxi1 sub vector into vXi1 vector, I optimize it by use less operations.

The history information at https://reviews.llvm.org/D68311

Reviewers: craig.topper, LuoYuanke, yubing, annita.zhang, pengfei, LiuChen3, RKSimon

Reviewed By: craig.topper

Subscribers: hiraditya, llvm-commits

Patch by Xiang Zhang (xiangzhangllvm)

Differential Revision: https://reviews.llvm.org/D71917