Clang 3.4 release notes: Fix description of enum increment/decrement change in
Clang 3.4. Add link to referenced PR.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_34@198626 91177308-0d34-0410-b5e6-96231b3b80d8
Merge branch 'release_34' into powerpc-darwin8-rel-3.4