Use MemoryExtensions.SequenceEqual in a few more places

Author: stephentoub

src/libraries/System.Data.Common/src/System/Data/DataKey.cs

@@ -168,20 +168,9 @@ internal bool Equals(DataKey value)
  {
  return false;
  }
- else if (column1.Length != column2.Length)
- {
- return false;
- }
  else
  {
- for (int i = 0; i < column1.Length; i++)
- {
- if (!column1[i].Equals(column2[i]))
- {
- return false;
- }
- }
- return true;
+ return column1.AsSpan().SequenceEqual(column2);
  }
  }
 

src/libraries/System.Data.Common/src/System/Data/RelatedView.cs

@@ -62,22 +62,7 @@ public bool Invoke(DataRow row, DataRowVersion version)
 
  object[] childValues = row.GetKeyValues(_childKey, version);
 
- bool allow = true;
- if (childValues.Length != parentValues.Length)
- {
- allow = false;
- }
- else
- {
- for (int i = 0; i < childValues.Length; i++)
- {
- if (!childValues[i].Equals(parentValues[i]))
- {
- allow = false;
- break;
- }
- }
- }
+ bool allow = childValues.AsSpan().SequenceEqual(parentValues);
 
  IFilter? baseFilter = base.GetFilter();
  if (baseFilter != null)

src/libraries/System.IO.UnmanagedMemoryStream/tests/ArrayHelpers.cs

@@ -53,21 +53,7 @@ private ArrayComparer() // use the static Instance singleton
  {
  }
 
- public bool Equals(T[] x, T[] y)
- {
- if (x.Length != y.Length)
- {
- return false;
- }
- for (int i = 0; i < x.Length; i++)
- {
- if (!EqualityComparer<T>.Default.Equals(x[i], y[i]))
- {
- return false;
- }
- }
- return true;
- }
+ public bool Equals(T[] x, T[] y) => x.AsSpan().SequenceEqual(y);
 
  public int GetHashCode(T[] obj)
  {

src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.cs

@@ -827,38 +827,15 @@ public bool HasSameRules(TimeZoneInfo other)
  return false;
  }
 
- bool sameRules;
  AdjustmentRule[]? currentRules = _adjustmentRules;
  AdjustmentRule[]? otherRules = other._adjustmentRules;
 
- sameRules =
- (currentRules == null && otherRules == null) ||
- (currentRules != null && otherRules != null);
-
- if (!sameRules)
+ if (currentRules is null || otherRules is null)
  {
- // AdjustmentRule array mismatch
- return false;
+ return currentRules == otherRules;
  }
 
- if (currentRules != null)
- {
- if (currentRules.Length != otherRules!.Length)
- {
- // AdjustmentRule array length mismatch
- return false;
- }
-
- for (int i = 0; i < currentRules.Length; i++)
- {
- if (!(currentRules[i]).Equals(otherRules[i]))
- {
- // AdjustmentRule value-equality mismatch
- return false;
- }
- }
- }
- return sameRules;
+ return currentRules.AsSpan().SequenceEqual(otherRules);
  }
 
  /// <summary>