[ARM] TypeSize lower bound for ARMCodeGenPrepare

We only try to promote types with are smaller than 16-bits, but we
also need to check that the type is not less than 8-bits.

Differential Revision: https://reviews.llvm.org/D50769


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339770 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed