[clang] [flang] [flang][driver] Rename `flang-new` as `flang` (PR #74377)

[Andrzej Warzyński via cfe-commits]

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@@ -193,26 +190,29 @@ driver, `clang -cc1` and consists of the following classes:
 This list is not exhaustive and only covers the main classes that implement the
 driver. The main entry point for the frontend driver, `fc1_main`, is
 implemented in `flang/tools/flang-driver/driver.cpp`. It can be accessed by
-invoking the compiler driver, `flang-new`, with the `-fc1` flag.
+invoking the compiler driver, `flang`, with the `-fc1` flag.
 
 The frontend driver will only run one action at a time. If you specify multiple
 action flags, only the last one will be taken into account. The default action
 is `ParseSyntaxOnlyAction`, which corresponds to `-fsyntax-only`. In other
-words, `flang-new -fc1 <input-file>` is equivalent to `flang-new -fc1 -fsyntax-only
+words, `flang -fc1 <input-file>` is equivalent to `flang -fc1 -fsyntax-only
 <input-file>`.
 
 ## The `flang-to-external-fc` script
-The `flang-to-external-fc` wrapper script for `flang-new` was introduced as a
-development tool and to facilitate testing. The `flang-to-external-fc` wrapper
-script will:
-* use `flang-new` to unparse the input source file (i.e. it will run `flang-new
-  -fc1 -fdebug-unparse <input-file>`), and then
+The `flang-to-external-fc` wrapper script for `flang` was introduced as a
+development tool and to facilitate testing. While code-generation is not
+available in Flang, you can use it as a drop-in replacement for other Fortran
+compilers in your build scripts.
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banach-space wrote:

Thank you for spotting this (yes, there _is_ code generation) and for the suggestion 🙏🏻  

I would actually like to reduce this paragraph and to eventually remove this script. So I will incorporate your suggestion only partially.

https://github.com/llvm/llvm-project/pull/74377