[flang] [clang] [flang][Driver] Let the linker fail on multiple definitions of main() (PR #73124)

[Andrzej Warzyński via cfe-commits]

banach-space wrote:

> @tblah @rj-jesus #74139 has landed. Can you please see if `-fno-fortran-main` helps to resolve your bugs?

Thanks!

>  I will write up a blog article about this and publish it. Maybe it would be worth documenting this as a question on StackOverflow, too?

Or a paragraph in Flang driver documentation? ;-)

https://github.com/llvm/llvm-project/pull/73124