Update a comment.

r279696, which changed `LLVM_CONSTEXPR AliasAttr` to `const AliasAttr`,
made this comment make less sense.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279699 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed