[llvm] CodeGen: replace assertions with explicit errors for landinpad lowering (PR #71287)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,18 @@
+; UNSUPPORTED: system-windows
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arsenm wrote:

This doesn't require windows. Also, don't use generic codegen tests. Move to a target 

https://github.com/llvm/llvm-project/pull/71287