[llvm] [BOLT][AArch64] Provide createDummyReturnFunction (PR #96626)

[Paschalis Mpeis via llvm-commits]

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@@ -2041,10 +2041,10 @@ class MCPlusBuilder {
     return InstructionListType();
   }
 
-  virtual InstructionListType createDummyReturnFunction(MCContext *Ctx) const {
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paschalis-mpeis wrote:

Thanks for your review. Done.

@yota9 yes, that was my intuition; I found implying that a function was created somewhat misleading.
`createReturn` is already used though, so we might go with something like: `createReturnBody`.
I will put up a follow-up NFC patch soon.

https://github.com/llvm/llvm-project/pull/96626