Consolidate Join/LeftJoin/RightJoin tuple overloads to use optional comparer parameter

Co-authored-by: eiriktsarpalis <2813363+eiriktsarpalis@users.noreply.github.com>

Author: Copilot

src/libraries/System.Linq.Queryable/ref/System.Linq.Queryable.cs

@@ -117,8 +117,7 @@ public static partial class Queryable
         public static System.Linq.IQueryable<TSource> Intersect<TSource>(this System.Linq.IQueryable<TSource> source1, System.Collections.Generic.IEnumerable<TSource> source2, System.Collections.Generic.IEqualityComparer<TSource>? comparer) { throw null; }
         public static System.Linq.IQueryable<TResult> Join<TOuter, TInner, TKey, TResult>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Linq.Expressions.Expression<System.Func<TOuter, TInner, TResult>> resultSelector) { throw null; }
         public static System.Linq.IQueryable<TResult> Join<TOuter, TInner, TKey, TResult>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Linq.Expressions.Expression<System.Func<TOuter, TInner, TResult>> resultSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer) { throw null; }
-        public static System.Linq.IQueryable<(TOuter Outer, TInner Inner)> Join<TOuter, TInner, TKey>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector) { throw null; }
-        public static System.Linq.IQueryable<(TOuter Outer, TInner Inner)> Join<TOuter, TInner, TKey>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer) { throw null; }
+        public static System.Linq.IQueryable<(TOuter Outer, TInner Inner)> Join<TOuter, TInner, TKey>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) { throw null; }
         public static TSource? LastOrDefault<TSource>(this System.Linq.IQueryable<TSource> source) { throw null; }
         public static TSource? LastOrDefault<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate) { throw null; }
         public static TSource LastOrDefault<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate, TSource defaultValue) { throw null; }
@@ -127,8 +126,7 @@ public static partial class Queryable
         public static TSource Last<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate) { throw null; }
         public static System.Linq.IQueryable<TResult> LeftJoin<TOuter, TInner, TKey, TResult>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Linq.Expressions.Expression<System.Func<TOuter, TInner?, TResult>> resultSelector) { throw null; }
         public static System.Linq.IQueryable<TResult> LeftJoin<TOuter, TInner, TKey, TResult>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Linq.Expressions.Expression<System.Func<TOuter, TInner?, TResult>> resultSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer) { throw null; }
-        public static System.Linq.IQueryable<(TOuter Outer, TInner? Inner)> LeftJoin<TOuter, TInner, TKey>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector) { throw null; }
-        public static System.Linq.IQueryable<(TOuter Outer, TInner? Inner)> LeftJoin<TOuter, TInner, TKey>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer) { throw null; }
+        public static System.Linq.IQueryable<(TOuter Outer, TInner? Inner)> LeftJoin<TOuter, TInner, TKey>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) { throw null; }
         public static long LongCount<TSource>(this System.Linq.IQueryable<TSource> source) { throw null; }
         public static long LongCount<TSource>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, bool>> predicate) { throw null; }
         public static TSource? MaxBy<TSource, TKey>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, TKey>> keySelector) { throw null; }
@@ -162,8 +160,7 @@ public static partial class Queryable
         public static System.Linq.IQueryable<TSource> Reverse<TSource>(this System.Linq.IQueryable<TSource> source) { throw null; }
         public static System.Linq.IQueryable<TResult> RightJoin<TOuter, TInner, TKey, TResult>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Linq.Expressions.Expression<System.Func<TOuter?, TInner, TResult>> resultSelector) { throw null; }
         public static System.Linq.IQueryable<TResult> RightJoin<TOuter, TInner, TKey, TResult>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Linq.Expressions.Expression<System.Func<TOuter?, TInner, TResult>> resultSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer) { throw null; }
-        public static System.Linq.IQueryable<(TOuter? Outer, TInner Inner)> RightJoin<TOuter, TInner, TKey>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector) { throw null; }
-        public static System.Linq.IQueryable<(TOuter? Outer, TInner Inner)> RightJoin<TOuter, TInner, TKey>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer) { throw null; }
+        public static System.Linq.IQueryable<(TOuter? Outer, TInner Inner)> RightJoin<TOuter, TInner, TKey>(this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<System.Func<TOuter, TKey>> outerKeySelector, System.Linq.Expressions.Expression<System.Func<TInner, TKey>> innerKeySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer = null) { throw null; }
         public static System.Linq.IQueryable<TResult> SelectMany<TSource, TResult>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, System.Collections.Generic.IEnumerable<TResult>>> selector) { throw null; }
         public static System.Linq.IQueryable<TResult> SelectMany<TSource, TResult>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, int, System.Collections.Generic.IEnumerable<TResult>>> selector) { throw null; }
         public static System.Linq.IQueryable<TResult> SelectMany<TSource, TCollection, TResult>(this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<System.Func<TSource, System.Collections.Generic.IEnumerable<TCollection>>> collectionSelector, System.Linq.Expressions.Expression<System.Func<TSource, TCollection, TResult>> resultSelector) { throw null; }