[AVR] Re-enable expansion of ADDE/ADDC/SUBE/SUBC in ISel

This was disabled in r333748, which broke four tests.

In the future, these need to be updated to UADDO/ADDCARRY or
USUBO/SUBCARRY.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338212 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed