[CIR] Make ZeroAttr use AttrBuilderWithInferredContext (llvm#136604)

This mirrors incubator changes from llvm/clangir#1576

Author: xlauko

clang/include/clang/CIR/Dialect/Builder/CIRBaseBuilder.h

@@ -83,21 +83,17 @@ class CIRBaseBuilderTy : public mlir::OpBuilder {
     return getConstPtrAttr(t, 0);
   }
 
-  mlir::TypedAttr getZeroAttr(mlir::Type t) {
-    return cir::ZeroAttr::get(getContext(), t);
-  }
-
   mlir::TypedAttr getZeroInitAttr(mlir::Type ty) {
     if (mlir::isa<cir::IntType>(ty))
       return cir::IntAttr::get(ty, 0);
     if (cir::isAnyFloatingPointType(ty))
       return cir::FPAttr::getZero(ty);
     if (auto arrTy = mlir::dyn_cast<cir::ArrayType>(ty))
-      return getZeroAttr(arrTy);
+      return cir::ZeroAttr::get(arrTy);
     if (auto ptrTy = mlir::dyn_cast<cir::PointerType>(ty))
       return getConstNullPtrAttr(ptrTy);
     if (auto recordTy = mlir::dyn_cast<cir::RecordType>(ty))
-      return getZeroAttr(recordTy);
+      return cir::ZeroAttr::get(recordTy);
     if (mlir::isa<cir::BoolType>(ty)) {
       return getFalseAttr();
     }

clang/include/clang/CIR/Dialect/IR/CIRAttrs.td

@@ -71,6 +71,13 @@ def ZeroAttr : CIR_Attr<"Zero", "zero", [TypedAttrInterface]> {
   }];
 
   let parameters = (ins AttributeSelfTypeParameter<"">:$type);
+
+  let builders = [
+    AttrBuilderWithInferredContext<(ins "mlir::Type":$type), [{
+      return $_get(type.getContext(), type);
+    }]>
+  ];
+
   let assemblyFormat = [{}];
 }
 

clang/lib/CIR/CodeGen/CIRGenExprConstant.cpp

@@ -183,7 +183,7 @@ emitArrayConstant(CIRGenModule &cgm, mlir::Type desiredType,
   }
 
   if (nonzeroLength == 0)
-    return cir::ZeroAttr::get(builder.getContext(), desiredType);
+    return cir::ZeroAttr::get(desiredType);
 
   const unsigned trailingZeroes = arrayBound - nonzeroLength;