Index: clang/lib/CodeGen/TargetInfo.cpp
===================================================================
--- clang/lib/CodeGen/TargetInfo.cpp
+++ clang/lib/CodeGen/TargetInfo.cpp
@@ -7490,12 +7490,9 @@
 
     // Check the fields.
     for (const auto *FD : RD->fields()) {
-      // For compatibility with GCC, ignore empty bitfields in C++ mode.
       // Unlike isSingleElementStruct(), empty structure and array fields
       // do count.  So do anonymous bitfields that aren't zero-sized.
-      if (getContext().getLangOpts().CPlusPlus &&
-          FD->isZeroLengthBitField(getContext()))
-        continue;
+
       // Like isSingleElementStruct(), ignore C++20 empty data members.
       if (FD->hasAttr<NoUniqueAddressAttr>() &&
           isEmptyRecord(getContext(), FD->getType(), true))
Index: clang/test/CodeGen/SystemZ/systemz-abi.cpp
===================================================================
--- clang/test/CodeGen/SystemZ/systemz-abi.cpp
+++ clang/test/CodeGen/SystemZ/systemz-abi.cpp
@@ -15,12 +15,10 @@
 // SOFT-FLOAT-LABEL: define{{.*}} void @_Z21pass_agg_double_class16agg_double_class(%class.agg_double_class* noalias sret(%class.agg_double_class) align 8 %{{.*}}, i64 %{{.*}})
 
 
-// For compatibility with GCC, this structure is passed in an FPR in C++,
-// but passed in a GPR in C (checked in systemz-abi.c).
-
+// This structure is passed in a GPR in C++ (and C, checked in systemz-abi.c).
 struct agg_float_cpp { float a; int : 0; };
 struct agg_float_cpp pass_agg_float_cpp(struct agg_float_cpp arg) { return arg; }
-// CHECK-LABEL: define{{.*}} void @_Z18pass_agg_float_cpp13agg_float_cpp(%struct.agg_float_cpp* noalias sret(%struct.agg_float_cpp) align 4 %{{.*}}, float %{{.*}})
+// CHECK-LABEL: define{{.*}} void @_Z18pass_agg_float_cpp13agg_float_cpp(%struct.agg_float_cpp* noalias sret(%struct.agg_float_cpp) align 4 %{{.*}}, i32 %{{.*}})
 // SOFT-FLOAT-LABEL:  define{{.*}} void @_Z18pass_agg_float_cpp13agg_float_cpp(%struct.agg_float_cpp* noalias sret(%struct.agg_float_cpp) align 4 %{{.*}}, i32 %{{.*}})