[llvm] [mlir] [OMPIRBuilder] Hoist alloca's to entry blocks of compiler-emitted GPU reduction functions (PR #181359)

[Pranav Bhandarkar via llvm-commits]

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@@ -4234,6 +4234,12 @@ Expected<Function *> OpenMPIRBuilder::createReductionFunction(
     }
 
   Builder.CreateRetVoid();
+
+  PostDominatorTree PostDomTree(*ReductionFunc);
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bhandarkar-pranav wrote:

A comment for the need to hoist allocas from `BB` to the entry block might be useful here. else, someone will have to `git blame` this to find out. 

https://github.com/llvm/llvm-project/pull/181359