[clang] Revert "Switch builtin strings to use string tables" (PR #119638)

[Chandler Carruth via cfe-commits]

chandlerc wrote:

> I'm going to bring out Windows buildbot back online that was failing so that when you do submit the revert, the bot should go back to green. I am looking into this and will get back to you on the original bug when I find something.

So, the builder came back up, and is now passing without this landing...

Here is the first build after it came back up: https://lab.llvm.org/buildbot/#/builders/46/builds/9173

And I went through the output and found a specific test that was failing, and it seems to pass?
```
PASS: Clang :: AST/builtins-arm-strex-rettype.c (433 of 81898)
```

So maybe this was a transient issue that has been fixed, or some stale state?

https://github.com/llvm/llvm-project/pull/119638