[CIR][CIRGen][NFC] Update buildPointerWithAlignment with LLVM upstrea…

…m codegen approach

clang/lib/CIR/CodeGen/CIRGenExpr.cpp

@@ -212,11 +212,25 @@ static Address buildPointerWithAlignment(const Expr *E,
     }
   }
 
+  // std::addressof and variants.
+  if (auto *Call = dyn_cast<CallExpr>(E)) {
+    switch (Call->getBuiltinCallee()) {
+    default:
+      break;
+    case Builtin::BIaddressof:
+    case Builtin::BI__addressof:
+    case Builtin::BI__builtin_addressof: {
+      llvm_unreachable("NYI");
+    }
+    }
+  }
+
   // TODO: conditional operators, comma.
+
   // Otherwise, use the alignment of the type.
-  CharUnits Align =
-      CGF.CGM.getNaturalPointeeTypeAlignment(E->getType(), BaseInfo);
-  return Address(CGF.buildScalarExpr(E), Align);
+  return CGF.makeNaturalAddressForPointer(
+      CGF.buildScalarExpr(E), E->getType()->getPointeeType(), CharUnits(),
+      /*ForPointeeType=*/true, BaseInfo, IsKnownNonNull);
 }
 
 /// Helper method to check if the underlying ABI is AAPCS

clang/lib/CIR/CodeGen/CIRGenFunction.h

@@ -1408,6 +1408,19 @@ class CIRGenFunction : public CIRGenTypeCache {
   LValue MakeNaturalAlignPointeeAddrLValue(mlir::Value V, clang::QualType T);
   LValue MakeNaturalAlignAddrLValue(mlir::Value V, QualType T);
 
+  /// Construct an address with the natural alignment of T. If a pointer to T
+  /// is expected to be signed, the pointer passed to this function must have
+  /// been signed, and the returned Address will have the pointer authentication
+  /// information needed to authenticate the signed pointer.
+  Address makeNaturalAddressForPointer(
+      mlir::Value Ptr, QualType T, CharUnits Alignment = CharUnits::Zero(),
+      bool ForPointeeType = false, LValueBaseInfo *BaseInfo = nullptr,
+      KnownNonNull_t IsKnownNonNull = NotKnownNonNull) {
+    if (Alignment.isZero())
+      Alignment = CGM.getNaturalTypeAlignment(T, BaseInfo, ForPointeeType);
+    return Address(Ptr, convertTypeForMem(T), Alignment, IsKnownNonNull);
+  }
+
   /// Load the value for 'this'. This function is only valid while generating
   /// code for an C++ member function.
   /// FIXME(cir): this should return a mlir::Value!