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

[Andrzej Warzyński via cfe-commits]

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@@ -339,11 +335,11 @@ just added using your new frontend option.
 
 ## CMake Support
 As of [#7246](https://gitlab.kitware.com/cmake/cmake/-/merge_requests/7246)
-(and soon to be released CMake 3.24.0), `cmake` can detect `flang-new` as a
+(and soon to be released CMake 3.24.0), `cmake` can detect `flang` as a
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banach-space wrote:

>  It seems like the check is through preprocessor macros defined by the different compilers.

Yes, thank you @hakostra 🙏🏻 

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