[compiler-rt] [sanitizer] intercept getservent_r, getservbyname_r, getservbyport_r (PR #133339)

[Thurston Dang via llvm-commits]

thurstond wrote:

The man page says
```
       getservent_r(), getservbyname_r(), getservbyport_r():
           Since glibc 2.19:
               _DEFAULT_SOURCE
           glibc 2.19 and earlier:
               _BSD_SOURCE || _SVID_SOURCE
```

Will this change upset our glibc 2.18 users?

https://github.com/llvm/llvm-project/pull/133339