getPristineRegs is not accurately considering shrink wrapping puts
registers not saved in certain blocks. Use explicit getCalleeSavedInfo
and isLiveIn instead.

This fixes pr32292.

Patch by Tim Shen!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299124 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed