x86: preserve flags when folding atomic operations

D4796 taught LLVM to fold some atomic integer operations into a single
instruction. The pattern was unaware that the instructions clobbered
flags. I fixed some of this issue in D13680 but had missed INC/DEC.

This patch adds the missing EFLAGS definition.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250438 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed