Created Unassigned: Stored Procs :: mapping many-many self reference to stored procedures throws if one overrides parameter names [1343]

```
public class Person
{
public int Id { get; set; }
public string Name { get; set; }
public ICollection<Person> Children { get; set; }
public ICollection<Person> Parents { get; set; }
}

public class MyContext : DbContext
{
public DbSet<Person> People { get; set; }

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Person>().HasMany(p => p.Children).WithMany(p => p.Parents);

modelBuilder.Entity<Person>().HasMany(p => p.Children).WithMany(p => p.Parents)
.MapToStoredProcedures(m => m.Insert(d => d.LeftKeyParameter(l => l.Id, "Left_id").RightKeyParameter(r => r.Id, "Right_Id")));
}
}
```

throws during EnableMigrations


__Sequence contains more than one matching element
__ at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source, Func`2 predicate)
at System.Data.Entity.ModelConfiguration.Configuration.ModificationFunctionConfiguration.ConfigureParameters(StorageModificationFunctionMapping modificationFunctionMapping)
at System.Data.Entity.ModelConfiguration.Configuration.ModificationFunctionConfiguration.Configure(StorageModificationFunctionMapping modificationFunctionMapping, DbProviderManifest providerManifest)
at System.Data.Entity.ModelConfiguration.Configuration.ModificationFunctionsConfiguration.Configure(StorageAssociationSetModificationFunctionMapping modificationFunctionMapping, DbProviderManifest providerManifest)
at System.Data.Entity.ModelConfiguration.Configuration.Properties.Navigation.NavigationPropertyConfiguration.Configure(StorageAssociationSetMapping associationSetMapping, DbDatabaseMapping databaseMapping, DbProviderManifest providerManifest)
at System.Data.Entity.ModelConfiguration.Configuration.Types.EntityTypeConfiguration.ConfigureAssociationMappings(DbDatabaseMapping databaseMapping, EntityType entityType, DbProviderManifest providerManifest)
at System.Data.Entity.ModelConfiguration.Configuration.Types.EntityTypeConfiguration.Configure(EntityType entityType, DbDatabaseMapping databaseMapping, DbProviderManifest providerManifest)
at System.Data.Entity.ModelConfiguration.Configuration.ModelConfiguration.ConfigureEntityTypes(DbDatabaseMapping databaseMapping, DbProviderManifest providerManifest)
at System.Data.Entity.ModelConfiguration.Configuration.ModelConfiguration.Configure(DbDatabaseMapping databaseMapping, DbProviderManifest providerManifest)
at System.Data.Entity.DbModelBuilder.Build(DbProviderManifest providerManifest, DbProviderInfo providerInfo)
at System.Data.Entity.DbModelBuilder.Build(DbConnection providerConnection)
at System.Data.Entity.Internal.LazyInternalContext.CreateModel(LazyInternalContext internalContext)
at System.Data.Entity.Internal.RetryLazy`2.GetValue(TInput input)
at System.Data.Entity.Internal.LazyInternalContext.InitializeContext()
at System.Data.Entity.Internal.LazyInternalContext.get_CodeFirstModel()
at System.Data.Entity.Infrastructure.EdmxWriter.WriteEdmx(DbContext context, XmlWriter writer)
at System.Data.Entity.Utilities.DbContextExtensions.<>c__DisplayClass1.<GetModel>b__0(XmlWriter w)
at System.Data.Entity.Utilities.DbContextExtensions.GetModel(Action`1 writeXml)
at System.Data.Entity.Utilities.DbContextExtensions.GetModel(DbContext context)
at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration, DbContext usersContext)
at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration)
at System.Data.Entity.Migrations.Design.MigrationScaffolder..ctor(DbMigrationsConfiguration migrationsConfiguration)
at System.Data.Entity.Migrations.Design.ToolingFacade.ScaffoldRunner.Run()
at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
at System.Data.Entity.Migrations.Design.ToolingFacade.Run(BaseRunner runner)
at System.Data.Entity.Migrations.Design.ToolingFacade.ScaffoldInitialCreate(String language, String rootNamespace)
at System.Data.Entity.Migrations.EnableMigrationsCommand.<>c__DisplayClass2.<.ctor>b__0()
at System.Data.Entity.Migrations.MigrationsDomainCommand.Execute(Action command)