tests/ui/sanitizer/hwaddress.rs: Run on aarch64 and remove cgu hack

To avoid linker errors like

    relocation truncated to fit: R_AARCH64_ADR_PREL_PG_HI21 against `.data.rel.ro..L.hwasan'

we need to have `-C target-feature=+tagged-globals`, which is documented here:
https://doc.rust-lang.org/beta/unstable-book/compiler-flags/sanitizer.html#hwaddresssanitizer

Author: Enselic

tests/ui/sanitizer/hwaddress.rs

@@ -1,11 +1,7 @@
 //@ needs-sanitizer-support
 //@ needs-sanitizer-hwaddress
 //
-// FIXME(#83706): this test triggers errors on aarch64-gnu
-//@ ignore-aarch64-unknown-linux-gnu
-//
-// FIXME(#83989): codegen-units=1 triggers linker errors on aarch64-gnu
-//@ compile-flags: -Z sanitizer=hwaddress -O -g -C codegen-units=16 -C unsafe-allow-abi-mismatch=sanitizer
+//@ compile-flags: -Z sanitizer=hwaddress -O -g -C target-feature=+tagged-globals -C unsafe-allow-abi-mismatch=sanitizer
 //
 //@ run-fail
 //@ error-pattern: HWAddressSanitizer: tag-mismatch

tests/ui/sanitizer/hwaddress.stderr

@@ -0,0 +1,6 @@
+warning: unknown and unstable feature specified for `-Ctarget-feature`: `tagged-globals`
+   |
+   = note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
+   = help: consider filing a feature request
+
+warning: 1 warning emitted