add a missing regression test for a DAGCombiner FDIV optimization

There's no test for this transform in any backend. Discovered
while debugging fast-math-flag propagation in the DAG (r244053).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244373 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed