Use more consistent argument validation in Immutable collection types

src/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.Builder.cs

@@ -798,8 +798,7 @@ public int IndexOf(T item, int startIndex, int count, IEqualityComparer<T>? equa
                     return -1;
                 }
 
-                Requires.Range(startIndex >= 0 && startIndex <= this.Count, nameof(startIndex));
-                Requires.Range(count >= 0 && (uint)(startIndex + count) <= (uint)this.Count, nameof(count));
+                Requires.ValidateRange(startIndex, count, this.Count, nameof(startIndex));
 
                 equalityComparer ??= EqualityComparer<T>.Default;
                 if (equalityComparer == EqualityComparer<T>.Default)
@@ -1002,8 +1001,7 @@ public void Sort(int index, int count, IComparer<T>? comparer)
             {
                 // Don't rely on Array.Sort's argument validation since our internal array may exceed
                 // the bounds of the publicly addressable region.
-                Requires.Range(index >= 0, nameof(index));
-                Requires.Range(count >= 0 && index + count <= this.Count, nameof(count));
+                Requires.ValidateRange(index, count, this.Count);
 
                 if (count > 1)
                 {

src/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.cs

@@ -173,8 +173,7 @@ public int IndexOf(T item, int startIndex, int count, IEqualityComparer<T>? equa
                 return -1;
             }
 
-            Requires.Range(startIndex >= 0 && startIndex <= self.Length, nameof(startIndex));
-            Requires.Range(count >= 0 && (uint)(startIndex + count) <= (uint)self.Length, nameof(count));
+            Requires.ValidateRange(startIndex, count, self.Length, nameof(startIndex));
 
             equalityComparer ??= EqualityComparer<T>.Default;
             if (equalityComparer == EqualityComparer<T>.Default)
@@ -826,8 +825,7 @@ public ImmutableArray<T> Sort(int index, int count, IComparer<T>? comparer)
         {
             ImmutableArray<T> self = this;
             self.ThrowNullRefIfNotInitialized();
-            Requires.Range(index >= 0, nameof(index));
-            Requires.Range(count >= 0 && index + count <= self.Length, nameof(count));
+            Requires.ValidateRange(index, count, self.Length);
 
             // 0 and 1 element arrays don't need to be sorted.
             if (count > 1)

src/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableDictionary_2.Builder.cs

@@ -329,8 +329,7 @@ void IDictionary.Remove(object key)
             void ICollection.CopyTo(Array array, int arrayIndex)
             {
                 Requires.NotNull(array, nameof(array));
-                Requires.Range(arrayIndex >= 0, nameof(arrayIndex));
-                Requires.Range(array.Length >= arrayIndex + this.Count, nameof(arrayIndex));
+                Requires.Range(arrayIndex >= 0 && (uint)(arrayIndex + this.Count) <= (uint)array.Length, nameof(arrayIndex));
 
                 foreach (KeyValuePair<TKey, TValue> item in this)
                 {

src/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableDictionary_2.cs

@@ -616,8 +616,7 @@ bool ICollection<KeyValuePair<TKey, TValue>>.Remove(KeyValuePair<TKey, TValue> i
         void ICollection<KeyValuePair<TKey, TValue>>.CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
         {
             Requires.NotNull(array, nameof(array));
-            Requires.Range(arrayIndex >= 0, nameof(arrayIndex));
-            Requires.Range(array.Length >= arrayIndex + this.Count, nameof(arrayIndex));
+            Requires.Range(arrayIndex >= 0 && (uint)(arrayIndex + this.Count) <= (uint)array.Length, nameof(arrayIndex));
 
             foreach (KeyValuePair<TKey, TValue> item in this)
             {
@@ -756,8 +755,7 @@ void IDictionary.Clear()
         void ICollection.CopyTo(Array array, int arrayIndex)
         {
             Requires.NotNull(array, nameof(array));
-            Requires.Range(arrayIndex >= 0, nameof(arrayIndex));
-            Requires.Range(array.Length >= arrayIndex + this.Count, nameof(arrayIndex));
+            Requires.Range(arrayIndex >= 0 && (uint)(arrayIndex + this.Count) <= (uint)array.Length, nameof(arrayIndex));
 
             foreach (KeyValuePair<TKey, TValue> item in this)
             {

src/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableHashSet_1.Builder.cs

@@ -393,8 +393,7 @@ void ICollection<T>.Add(T item)
             void ICollection<T>.CopyTo(T[] array, int arrayIndex)
             {
                 Requires.NotNull(array, nameof(array));
-                Requires.Range(arrayIndex >= 0, nameof(arrayIndex));
-                Requires.Range(array.Length >= arrayIndex + this.Count, nameof(arrayIndex));
+                Requires.Range(arrayIndex >= 0 && (uint)(arrayIndex + this.Count) <= (uint)array.Length, nameof(arrayIndex));
 
                 foreach (T item in this)
                 {

src/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableHashSet_1.cs

@@ -492,8 +492,7 @@ bool ICollection<T>.IsReadOnly
         void ICollection<T>.CopyTo(T[] array, int arrayIndex)
         {
             Requires.NotNull(array, nameof(array));
-            Requires.Range(arrayIndex >= 0, nameof(arrayIndex));
-            Requires.Range(array.Length >= arrayIndex + this.Count, nameof(arrayIndex));
+            Requires.Range(arrayIndex >= 0 && (uint)(arrayIndex + this.Count) <= (uint)array.Length, nameof(arrayIndex));
 
             foreach (T item in this)
             {
@@ -537,8 +536,7 @@ bool ICollection<T>.Remove(T item)
         void ICollection.CopyTo(Array array, int arrayIndex)
         {
             Requires.NotNull(array, nameof(array));
-            Requires.Range(arrayIndex >= 0, nameof(arrayIndex));
-            Requires.Range(array.Length >= arrayIndex + this.Count, nameof(arrayIndex));
+            Requires.Range(arrayIndex >= 0 && (uint)(arrayIndex + this.Count) <= (uint)array.Length, nameof(arrayIndex));
 
             foreach (T item in this)
             {

src/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList.cs

@@ -298,11 +298,6 @@ public static int LastIndexOf<T>(this IImmutableList<T> list, T item, int startI
         {
             Requires.NotNull(list, nameof(list));
 
-            if (list.Count == 0 && startIndex == 0)
-            {
-                return -1;
-            }
-
             return list.LastIndexOf(item, startIndex, startIndex + 1, EqualityComparer<T>.Default);
         }