[flang] [clang] [flang][driver] Add -fno-fortran-main (link time) option to remove Fortran_main from link line (PR #74139)

[Andrzej Warzyński via cfe-commits]

================
@@ -6345,6 +6345,10 @@ def J : JoinedOrSeparate<["-"], "J">,
   Group<gfortran_Group>,
   Alias<module_dir>;
 
+def no_fortran_main : Flag<["-"], "fno-fortran-main">,
+  Visibility<[FlangOption]>, Group<f_Group>,
+  HelpText<"Don't link in Fortran main">;
+
----------------
banach-space wrote:

```suggestion
def J : JoinedOrSeparate<["-"], "J">,
  Flags<[RenderJoined]>, Visibility<[FlangOption, FC1Option]>,
  Group<gfortran_Group>,
  Alias<module_dir>;
  
} // let Visibility = [FC1Option, FlangOption]
//===----------------------------------------------------------------------===//
// FLang Options
//===----------------------------------------------------------------------===//
let Visibility = [FlangOption] in {
def no_fortran_main : Flag<["-"], "fno-fortran-main">,
  Visibility<[FlangOption]>, Group<f_Group>,
  HelpText<"Don't link in Fortran main">;
}
} // let Visibility = [ FlangOption]
```

I hope this suggestion is clear - sadly GitHub is not allowing me to make a proper suggestion for the code above of what you added. 

https://github.com/llvm/llvm-project/pull/74139