[clang] [flang] [llvm] [openmp] [flang][driver] rename flang-new to flang (PR #110023)

[Håkon Strandenes via cfe-commits]

hakostra wrote:

I have freshly compiled and installed LLVM flang after the rename. I have:

```
$ ll flang*
lrwxrwxrwx 1 hakostra hakostra         8 okt.  15 17:03 flang -> flang-20*
-rwxr-xr-x 1 hakostra hakostra 176517648 okt.  23 12:03 flang-20*
lrwxrwxrwx 1 hakostra hakostra         5 okt.  23 12:13 flang-new -> flang*
$ ll clang*
lrwxrwxrwx 1 hakostra hakostra         8 okt.  15 17:03 clang -> clang-20*
lrwxrwxrwx 1 hakostra hakostra         5 okt.  23 12:13 clang++ -> clang*
-rwxr-xr-x 1 hakostra hakostra 156923176 okt.  23 11:49 clang-20*
```

so `flang-20` and `clang-20` are the actual binaries, `flang` and `clang` are symlinks to these. Also, on my system, `/usr/bin/gcc` is just a symlink to whatever `gcc` version I have, for in my case `/usr/bin/gcc-13`. Same for `gfortran`. So it's the same naming scheme.

This is intended behavior. If `flang` was the name of the binary and `flang-20` the symlink, it would not be possible to have several versions installed in besides each other.

https://github.com/llvm/llvm-project/pull/110023