Due to the fact that the windows unwinding has the concept of chained frames, we
maintain a current frame info pointer that is adjusted on any push and pop of a
unwinding context. This just removes an unnecessary variable that was used to
mirror the DWARF unwinding code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212882 91177308-0d34-0410-b5e6-96231b3b80d8