[clang] [llvm] [TargetParser][ARM][NFC] Make string tables reloc-free (PR #206937)

[Alexis Engelke via llvm-commits]

aengelke wrote:

In addition to reducing .data.rel.ro, this [also slightly reduces the time it takes to build LLVM](https://llvm-compile-time-tracker.com/compare.php?from=6e4eebc91c109e81ce4f5dc3df45fb04ec3b6ba4&to=27ecf2b1e2abcbf56f4be95af9cd27bdae434d41&stat=size-data).

https://github.com/llvm/llvm-project/pull/206937