[llvm] [StructuralHash] Refactor (PR #112621)

[Ellis Hoag via llvm-commits]

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@@ -121,14 +148,17 @@ class StructuralHashImpl {
       // This random value acts as a block header, as otherwise the partition of
       // opcodes into BBs wouldn't affect the hash, only the order of the
       // opcodes
-      hash(45798);
+      Hashes.emplace_back(45798);
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ellishg wrote:

Can we hash a string (maybe "BasicBlock Start"?) rather than an arbitrary number to make it more obvious what we are doing? Same for `23456` below.

https://github.com/llvm/llvm-project/pull/112621