Correct mustCallSuper documentation as per analyzer impl

See must_call_super_test.dart for tests covered by this documentation.

Bug: https://github.com/dart-lang/sdk/issues/49499
Change-Id: I50e6546dda155cb133b8ad314db27a266a94fa00
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/252762
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Samuel Rawlins <srawlins@google.com>
diff --git a/pkg/meta/lib/meta.dart b/pkg/meta/lib/meta.dart
index 2f2fbf3..7a1ce9f 100644
--- a/pkg/meta/lib/meta.dart
+++ b/pkg/meta/lib/meta.dart
@@ -191,19 +191,20 @@
 ///   and does not directly declare a concrete override of `noSuchMethod`.
 const _MustBeOverridden mustBeOverridden = _MustBeOverridden();
 
-/// Used to annotate an instance method `m`. Indicates that every invocation of
-/// a method that overrides `m` must also invoke `m`. In addition, every method
-/// that overrides `m` is implicitly annotated with this same annotation.
+/// Used to annotate an instance member (method, getter, setter, operator, or
+/// field) `m`. Indicates that every invocation of a member that overrides `m`
+/// must also invoke `m`. In addition, every method that overrides `m` is
+/// implicitly annotated with this same annotation.
 ///
-/// Note that private methods with this annotation cannot be validly overridden
-/// outside of the library that defines the annotated method.
+/// Note that private members with this annotation cannot be validly overridden
+/// outside of the library that defines the annotated member.
 ///
 /// Tools, such as the analyzer, can provide feedback if
 ///
-/// * the annotation is associated with anything other than an instance method,
+/// * the annotation is associated with anything other than an instance member,
 ///   or
-/// * a method that overrides a method that has this annotation can return
-///   without invoking the overridden method.
+/// * a member that overrides a member that has this annotation can return
+///   without invoking the overridden member.
 const _MustCallSuper mustCallSuper = _MustCallSuper();
 
 /// Used to annotate an instance member (method, getter, setter, operator, or