[InlineSpiller] Don't call TargetInstrInfo::foldMemoryOperand with an empty list.

Since r287792 if we try to do that we will hit an assert.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289001 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed