[clang] [CIR] Upstream StackSave and StackRestoreOp (PR #136426)

[Bruno Cardoso Lopes via cfe-commits]

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@@ -1419,6 +1419,48 @@ def CallOp : CIR_CallOpBase<"call", [NoRegionArguments]> {
     }]>];
 }
 
+//===----------------------------------------------------------------------===//
+// StackSave & StackRestoreOp
+//===----------------------------------------------------------------------===//
+
+def StackSaveOp : CIR_Op<"stack_save"> {
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bcardosolopes wrote:

Thanks for bringing up the consistency angle here. We have been telling people to use `snake_case`: https://llvm.github.io/clangir/Dialect/cir-style-guide.html, though I see a good point in matching LLVM when it makes sense (like in this case). I don't have a strong opinion here other than bigger names looks better with `_` breaking them down. Maybe we should extend the doc to make things similar to LLVM when is the case?

https://github.com/llvm/llvm-project/pull/136426