[clang] [CIR] Upstream AtomicFenceOp and signal/thread fence builtins (PR #168346)

[Sirui Mu via cfe-commits]

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@@ -58,6 +58,28 @@ static RValue emitBuiltinBitOp(CIRGenFunction &cgf, const CallExpr *e,
   return RValue::get(result);
 }
 
+static mlir::Value makeAtomicFenceValue(CIRGenFunction &cgf,
+                                        const CallExpr *expr,
+                                        cir::SyncScopeKind syncScope) {
+  auto &builder = cgf.getBuilder();
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Lancern wrote:

```suggestion
  CIRGenBuilderTy &builder = cgf.getBuilder();
```

https://github.com/llvm/llvm-project/pull/168346