Make a CodeGen test more robust against vector register selection

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208351 91177308-0d34-0410-b5e6-96231b3b80d8
Use range loops.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208353 91177308-0d34-0410-b5e6-96231b3b80d8
[InstCombine] Some cleanup in optimization of redundant insertvalue instructions.
And one more test added.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208355 91177308-0d34-0410-b5e6-96231b3b80d8