[Docs] Updating CMake docs to include LLVM_REVERSE_ITERATION

Reviewers: beanz, mehdi_amini

Reviewed By: beanz

Subscribers: mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D35080

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307560 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed