[llvm] [TableGen] Rework error reporting for duplicate Feature/Processor. (PR #102257)

[Tomas Matheson via llvm-commits]

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@@ -1,6 +1,3 @@
-// Temporarily disable test due to non-deterministic order of error messages.
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tmatheson-arm wrote:

For future reference, I think it would have been better to revert the original until fixed.

https://github.com/llvm/llvm-project/pull/102257