Add missing namespace

Author: andrewlock

tests/NetEscapades.EnumGenerators.IntegrationTests/Enums.cs

@@ -63,6 +63,8 @@ namespace NetEscapades.EnumGenerators.Nuget.IntegrationTests
 namespace NetEscapades.EnumGenerators.Nuget.Interceptors.IntegrationTests
 #elif NUGET_NETSTANDARD_INTERCEPTOR_TESTS
 namespace NetEscapades.EnumGenerators.Nuget.NetStandard.Interceptors.IntegrationTests
+#elif NUGET_SYSTEMMEMORY_INTEGRATION_TESTS
+namespace NetEscapades.EnumGenerators.Nuget.SystemMemory.IntegrationTests
 #else
 #error Unknown integration tests
 #endif