LLVM 13.0 is available in Fedora 35. I have made some tests in a Fedora Rawhide virtual machine. There is flang-new, which can’t produce yet an executable:
$ flang-new --version
flang-new version 13.0.0 (Fedora 13.0.0~rc1-1.fc35)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
$ flang-new hello.f90
error: code-generation is not available yet
and the flang script:
$ flang --version
flang version 13.0.0
$ flang hello.f90
$ ./a.out
Hello World!