Use CopyTo(arr) instead of creating List<T> first (#36228)

* Use LINQ ToArray * Update RoType.cs * Update RoType.cs * Update src/libraries/System.Reflection.MetadataLoadContext/src/System/Reflection/TypeLoading/Types/RoType.cs Co-authored-by: Stephen Toub <stoub@microsoft.com> * Fix whitespace causing analyzer warnings Co-authored-by: Stephen Toub <stoub@microsoft.com>

Author: Youssef1313

src/libraries/System.Reflection.MetadataLoadContext/src/System/Reflection/TypeLoading/Types/RoType.cs

@@ -192,9 +192,14 @@ private RoType[] ComputeInterfaceClosure()
  }
  }
 
- // todo: use IEnumerable<T> extension: return ifcs.ToArray()
- List<RoType> list = new List<RoType>(ifcs);
- return list.ToArray();
+ if (ifcs.Count == 0)
+ {
+ return Array.Empty<RoType>();
+ }
+
+ var arr = new RoType[ifcs.Count];
+ ifcs.CopyTo(arr);
+ return arr;
  }
 
  private volatile RoType[]? _lazyInterfaces;