[llvm] [NFC][LLVM] Namespace cleanup in AddressSanitizer/ControlHeightReduction (PR #163776)

[Thurston Dang via llvm-commits]

thurstond wrote:

> Adjusted the title. It's not stray since both changes are essentially the same issue

Thanks for updating!

Typically it's easier to get changes reviewed/approved if they are split up by topic. But in this case I guess it's simple enough.

https://github.com/llvm/llvm-project/pull/163776