Revert "Add "last" setter to List."

sdk/lib/core/list.dart

Index: sdk/lib/core/list.dart
diff --git a/sdk/lib/core/list.dart b/sdk/lib/core/list.dart
index aa0d4d34803fdd1f3ad49bc5bd358d62316cfadb..0b55b8ec0384ad67df417af79f14fc0b5257cab6 100644
--- a/sdk/lib/core/list.dart
+++ b/sdk/lib/core/list.dart
@@ -154,16 +154,6 @@ abstract class List<E> implements Iterable<E>, EfficientLength {
   void set length(int newLength);
 
   /**
-   * Replaces the last element of the list with [value].
-   *
-   * Using `list.last = value` is equivalent to `list[list.length - 1] = value`,
-   * only shorter and more readable.
-   *
-   * The list must be modifiable and must have a length greater than zero.
-   */
-  void set last(E value);
-
-  /**
    * Adds [value] to the end of this list,
    * extending the length by one.
    *