[clang-tools-extra] [clang] [llvm] [X86] Emit Warnings for frontend options to enable knl/knm specific ISAs. (PR #75580)

[Simon Pilgrim via cfe-commits]

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@@ -933,6 +933,9 @@ X86 Support
 - Support ISA of ``AVX10.1``.
 - ``-march=pantherlake`` and ``-march=clearwaterforest`` are now supported.
 - Added ABI handling for ``__float128`` to match with GCC.
+- Emit Warnings for clang options to enable knl/knm. From next version
+  (LLVM 19), all-end supports on knl/knm and other Xeon Phi targets will be
+  removed.
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RKSimon wrote:

This needs rephrasing - to list all the ISAs that are deprecated and the intrinsics will be removed.

https://github.com/llvm/llvm-project/pull/75580