[flang-commits] [flang] [Flang] Add Sphinx man page support for Flang (PR #141882)

[Samarth Narang via flang-commits]

snarang181 wrote:

Hi @kiranchandramohan @tarunprabhu, with my latest commit the html target is built without any warnings. When I trigger the man build via `ninja docs-flang-man`, 
I see
```
WARNING: toctree contains reference to nonexisting document 'FIRLangRef'
WARNING: toctree contains reference to nonexisting document 'FlangCommandLineReference'
```
If we build with `-DSPHINX_WARNINGS_AS_ERRORS=OFF`, this will lead to the man page successfully being built. If the flag is not set, we will hit a fatal error and fail the man build. Should we add this as a TODO and open another issue for that? I think this patch is tailored for the missing `man_config` issue and `man` not being built at all. Let me know what you guys think. 

https://github.com/llvm/llvm-project/pull/141882