[clang] [flang] [flang][Driver] Support -print-supported-extensions (PR #117402)

[Andrzej Warzyński via cfe-commits]

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@@ -0,0 +1,34 @@
+! REQUIRES: arm-registered-target
+
+! RUN: %flang --target=arm-linux-gnu --print-supported-extensions 2>&1 \
+! RUN:   | FileCheck --strict-whitespace --implicit-check-not=FEAT_ %s
+
+! CHECK: All available -march extensions for ARM
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banach-space wrote:

If the implementation in Clang and Flang are identical, then it should be re-used rather than re-implemented. Such "hooks" usually end up in:
*  https://github.com/llvm/llvm-project/blob/main/clang/lib/Driver/ToolChains/CommonArgs.cpp.

We are definitely missing some better way to organise these things.

Anyway, thanks for working on this!

https://github.com/llvm/llvm-project/pull/117402