Re-commit "[IR] Add NODISCARD to attribute functions"

Now that https://reviews.llvm.org/D55435 is committed,
https://reviews.llvm.org/D55217 can be committed once again -- all warnings are
now fixed.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@348733 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed