LSR shouldn't ever try to hack on integer IV's larger than 64-bits.  Right now
it is not APInt clean, but even when it is it needs to be evaluated carefully
to determine whether it is actually profitable.

This fixes a crash on PR3806


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67134 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed