[llvm] [MC] Fix quadratic runtime within alignment boundary fragment relaxation (PR #176535)

[Fangrui Song via llvm-commits]

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@@ -0,0 +1,28 @@
+// REQUIRES: asserts
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MaskRay wrote:

Consider `# ` for REQUIRE/RUN/CHECK and `## ` for other comments.

https://github.com/llvm/llvm-project/pull/176535