Enable CompressedTupleTest.NestedEbo test case.

PiperOrigin-RevId: 766707922
Change-Id: Ibb10a5e992665673e2bd918439429b79dbe78fbf

Author: ezbr

absl/container/internal/compressed_tuple_test.cc

@@ -107,14 +107,6 @@ TEST(CompressedTupleTest, PointerToEmpty) {
   }
 }
 
-TEST(CompressedTupleTest, NestedCompressedTuplePreservesEmptiness) {
-  using TupleType = CompressedTuple<Empty<0>, CompressedTuple<Empty<0>>>;
-  TupleType x;
-  EXPECT_EQ(x.get<0>().value(), CallType::kMutableRef);
-  EXPECT_EQ(x.get<1>().get<0>().value(), CallType::kMutableRef);
-  EXPECT_TRUE(std::is_empty_v<TupleType>);
-}
-
 TEST(CompressedTupleTest, OneMoveOnRValueConstructionTemp) {
   InstanceTracker tracker;
   CompressedTuple<CopyableMovableInstance> x1(CopyableMovableInstance(1));
@@ -460,14 +452,15 @@ TEST(CompressedTupleTest, EmptyFinalClass) {
 }
 #endif
 
-// TODO(b/214288561): enable this test.
-TEST(CompressedTupleTest, DISABLED_NestedEbo) {
+TEST(CompressedTupleTest, NestedEbo) {
   struct Empty1 {};
   struct Empty2 {};
   CompressedTuple<Empty1, CompressedTuple<Empty2>, int> x;
   CompressedTuple<Empty1, Empty2, int> y;
-  // Currently fails with sizeof(x) == 8, sizeof(y) == 4.
   EXPECT_EQ(sizeof(x), sizeof(y));
+
+  using NestedEmpty = CompressedTuple<Empty1, CompressedTuple<Empty2>>;
+  EXPECT_TRUE(std::is_empty_v<NestedEmpty>);
 }
 
 }  // namespace