[X86][AVX512]Improving shuffle lowering by using AVX-512 EXPAND* instructions

This patch fix PR31351: https://llvm.org/bugs/show_bug.cgi?id=31351

1.  This patch adds new type of shuffle lowering
2.  We can use the expand instruction, When the shuffle pattern is as following:
    { 0*a[0]0*a[1]...0*a[n] , n >=0 where a[] elements in a ascending order}.

Reviewers: 1. igorb  
           2. guyblank  
           3. craig.topper  
           4. RKSimon 

Differential Revision: https://reviews.llvm.org/D28352



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291584 91177308-0d34-0410-b5e6-96231b3b80d8