[lld] [LLD, MachO] Add `getUnwindInfoEncodingHash` to `BPSectionOrderer.cpp`. (PR #105587)

[Peter Rong via llvm-commits]

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@@ -60,6 +61,30 @@ getRelocHash(const Reloc &reloc,
   return getRelocHash(kind, sectionIdx.value_or(0), 0, reloc.addend);
 }
 
+// Get a hash of the unwind info (after relocation).
+// This hash is not 100% accurate, but it's good enough for compression.
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DataCorrupted wrote:

Proposing `Hash(lsda->getName() + personality->getName() + utohexstr(encoding))` (name is "<null>" if it is a nullpointer)

https://github.com/llvm/llvm-project/pull/105587