Trying to unbreak the darwin11 builder

The CR bit tracking code broke PPC/Darwin; trying to get it working again...

(the darwin11 builder, which defaults to the darwin ABI when running PPC tests,
asserted when running test/CodeGen/PowerPC/inverted-bool-compares.ll)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202459 91177308-0d34-0410-b5e6-96231b3b80d8