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

[Freddy Ye via cfe-commits]

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@@ -18,7 +18,7 @@ This test serves two purposes:
 
 The list of warnings below should NEVER grow.  It should gradually shrink to 0.
 
-CHECK: Warnings without flags (65):
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FreddyLeaf wrote:

agree. Will add a warning group. sorry for misleading info above.

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