[clang] [CIR] Upstream zero init for global variables (PR #133100)

[Amr Hesham via cfe-commits]

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@@ -67,6 +67,40 @@ class CIRBaseBuilderTy : public mlir::OpBuilder {
     return create<cir::ConstantOp>(loc, attr.getType(), attr);
   }
 
+  mlir::TypedAttr getConstNullPtrAttr(mlir::Type t) {
+    assert(mlir::isa<cir::PointerType>(t) && "expected cir.ptr");
+    return getConstPtrAttr(t, 0);
+  }
+
+  mlir::TypedAttr getZeroAttr(mlir::Type t) {
+    return cir::ZeroAttr::get(getContext(), t);
+  }
+
+  mlir::TypedAttr getZeroInitAttr(mlir::Type ty) {
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AmrDeveloper wrote:

We need to update this function in the incubator to add the missing types @andykaylor 

https://github.com/llvm/llvm-project/pull/133100