[llvm] [SPIRV] Fix code quality issues. (PR #152005)

[Nathan Gauër via llvm-commits]

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@@ -73,7 +73,12 @@ class ConvergenceRegion {
         Entry(std::move(CR.Entry)), Exits(std::move(CR.Exits)),
         Blocks(std::move(CR.Blocks)) {}
 
+  // Destructor.
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Keenuts wrote:

comment is not useful.

https://github.com/llvm/llvm-project/pull/152005