InstCombine: Don't combine loads/stores from swifterror to a new type

This generates invalid IR: the only users of swifterror can be call
arguments, loads, and stores.

rdar://28242257

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281144 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed