[llvm] [MC,CodeGen] Update .prefalign for symbol-based preferred alignment (PR #184032)

[Fangrui Song via llvm-commits]

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@@ -170,6 +171,11 @@ LLVM_DUMP_METHOD void MCFragment::dump() const {
        << " Size:" << BF->getSize();
     break;
   }
+  case MCFragment::FT_PrefAlign:
+    OS << " PrefAlign:" << getPrefAlignPreferred().value()
+       << " End:" << getPrefAlignEnd().getName()
+       << " ComputedAlign:" << getPrefAlignComputed().value();
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MaskRay wrote:

`Align ComputedAlign` is default-initialized to 1 (shift value 0) if it hasn't been assigned by relaxPrefAlign

https://github.com/llvm/llvm-project/pull/184032