[lld] [lld][ELF] Demote symbols in discarded sections to Undefined. (PR #68777)

[Fangrui Song via llvm-commits]

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@@ -0,0 +1,14 @@
+# REQUIRES: x86
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MaskRay wrote:

This is copied from discard-section.s but adds `-r`. We should use the same file: https://maskray.me/blog/2021-08-08-toolchain-testing#i-dont-know-an-existing-test-can-be-enhanced

https://github.com/llvm/llvm-project/pull/68777