[flang-commits] [flang] [flang][docs] Do not recommend FLANG_ENABLE_WERROR=ON (PR #171152)

[Leandro Lupori via flang-commits]

luporl wrote:

`-Werror` is well tested when building flang with LLVM (at least with recent versions).
Most (all?) buildbots that build flang with LLVM have `FLANG_ENABLE_WERROR=ON`, which means flang developers are expected to not introduce new warnings.

https://github.com/llvm/llvm-project/pull/171152