[llvm] [MC] Add support for -mcpu=native. (PR #159414)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,3 @@
+# RUN: llvm-mc -filetype=obj -mcpu=native %s 2>&1 | FileCheck %s
+
+# CHECK-NOT: 'native' is not a recognized processor for this target (ignoring processor)
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arsenm wrote:

I guess checking native works though 

https://github.com/llvm/llvm-project/pull/159414