[llvm] [LLVM][Triple] Drop unknown object types from normalized triples (PR #135571)

[Usman Nadeem via llvm-commits]

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@@ -1265,6 +1266,14 @@ std::string Triple::normalize(StringRef Str, CanonicalForm Form) {
     }
   }
 
+  // Environment "unknown-elf" is just "elf".
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UsmanNadeem wrote:

Added more reviewers to get additional opinion.

https://github.com/llvm/llvm-project/pull/135571