Add the missing inline namespace to the nullability files

PiperOrigin-RevId: 642621989
Change-Id: I95efa4bd9fe8fe3c449304706401374f851f0fbe

absl/base/BUILD.bazel

@@ -87,6 +87,7 @@ cc_library(
     copts = ABSL_DEFAULT_COPTS,
     linkopts = ABSL_DEFAULT_LINKOPTS,
     deps = [
+        ":config",
         ":core_headers",
         "//absl/meta:type_traits",
     ],

absl/base/CMakeLists.txt

@@ -75,6 +75,7 @@ absl_cc_library(
   SRCS
     "internal/nullability_impl.h"
   DEPS
+    absl::config
     absl::core_headers
     absl::type_traits
   COPTS

absl/base/internal/nullability_impl.h

@@ -19,10 +19,11 @@
 #include <type_traits>
 
 #include "absl/base/attributes.h"
+#include "absl/base/config.h"
 #include "absl/meta/type_traits.h"
 
 namespace absl {
-
+ABSL_NAMESPACE_BEGIN
 namespace nullability_internal {
 
 // `IsNullabilityCompatible` checks whether its first argument is a class
@@ -101,6 +102,7 @@ using NullabilityUnknownImpl
     = T;
 
 }  // namespace nullability_internal
+ABSL_NAMESPACE_END
 }  // namespace absl
 
 #endif  // ABSL_BASE_INTERNAL_NULLABILITY_IMPL_H_

absl/base/nullability.h

@@ -150,9 +150,11 @@
 #ifndef ABSL_BASE_NULLABILITY_H_
 #define ABSL_BASE_NULLABILITY_H_
 
+#include "absl/base/config.h"
 #include "absl/base/internal/nullability_impl.h"
 
 namespace absl {
+ABSL_NAMESPACE_BEGIN
 
 // absl::Nonnull
 //
@@ -219,6 +221,7 @@ using Nullable = nullability_internal::NullableImpl<T>;
 template <typename T>
 using NullabilityUnknown = nullability_internal::NullabilityUnknownImpl<T>;
 
+ABSL_NAMESPACE_END
 }  // namespace absl
 
 #endif  // ABSL_BASE_NULLABILITY_H_