[llvm] hwasan: Fix relocation errors by adjusting `NewGV` alias address calculation (PR #164876)

[Peter Collingbourne via llvm-commits]

pcc wrote:

The tag in the symbol address is deliberate. This change would break accessing an address-taken global because the accesses would not be using the correct tag. The fix is likely to modify the Rust compiler to ensure that the `tagged-globals` feature is enabled when building with HWASan.

It looks like the Rust compiler documentation mentions `tagged-globals` [here](https://doc.rust-lang.org/beta/unstable-book/compiler-flags/sanitizer.html#hwaddresssanitizer). What is unclear is why the Rust compiler developers chose to require users to manually specify the attribute instead of that being implicit when building with HWASan, as Clang does.

https://github.com/llvm/llvm-project/pull/164876