[analyzer] Remove corresponding{Getter,Setter} from fragment APIs.

It doesn't make sense to ask a getter/setter fragment what its
corresponding setter/getter is. It only makes sense to ask that
question of a getter/setter element.

Change-Id: Ie4cca352db8943f697b306e1d26035f5abac7722
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/412180
Commit-Queue: Paul Berry <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: stereotype441

pkg/analyzer/api.txt

@@ -3872,7 +3872,6 @@ package:analyzer/dart/element/element2.dart:
     fragments (getter: List<GetterFragment>)
   GetterFragment (class extends Object implements PropertyAccessorFragment):
     new (constructor: GetterFragment Function())
-    correspondingSetter2 (getter: SetterFragment?)
     element (getter: GetterElement)
     nextFragment (getter: GetterFragment?)
     previousFragment (getter: GetterFragment?)
@@ -4205,7 +4204,6 @@ package:analyzer/dart/element/element2.dart:
     fragments (getter: List<SetterFragment>)
   SetterFragment (class extends Object implements PropertyAccessorFragment):
     new (constructor: SetterFragment Function())
-    correspondingGetter2 (getter: GetterFragment?)
     element (getter: SetterElement)
     nextFragment (getter: SetterFragment?)
     previousFragment (getter: SetterFragment?)

pkg/analyzer/lib/dart/element/element2.dart

@@ -1177,10 +1177,6 @@ abstract class GetterElement implements PropertyAccessorElement2 {
 ///
 /// Clients may not extend, implement or mix-in this class.
 abstract class GetterFragment implements PropertyAccessorFragment {
-  /// The setter that corresponds to (has the same name as) this getter, or
-  /// `null` if there is no corresponding setter.
-  SetterFragment? get correspondingSetter2;
-
   @override
   GetterElement get element;
 
@@ -2490,10 +2486,6 @@ abstract class SetterElement implements PropertyAccessorElement2 {
 ///
 /// Clients may not extend, implement or mix-in this class.
 abstract class SetterFragment implements PropertyAccessorFragment {
-  /// The getter that corresponds to (has the same name as) this setter, or
-  /// `null` if there is no corresponding getter.
-  GetterFragment? get correspondingGetter2;
-
   @override
   SetterElement get element;
 

pkg/analyzer/lib/src/dart/element/element.dart

@@ -5633,7 +5633,7 @@ class GetterElementImpl extends PropertyAccessorElementImpl2
 
   @override
   SetterElement? get correspondingSetter2 =>
-      firstFragment.correspondingSetter2?.element;
+      firstFragment.variable2?.setter?.element;
 
   @override
   List<GetterFragmentImpl> get fragments {
@@ -5699,9 +5699,6 @@ class GetterFragmentImpl extends PropertyAccessorElementImpl
   @override
   PropertyAccessorElement? get correspondingSetter => variable2?.setter;
 
-  @override
-  SetterFragment? get correspondingSetter2 => variable2?.setter;
-
   @override
   GetterElementImpl get element {
     if (_element != null) {
@@ -10714,7 +10711,7 @@ class SetterElementImpl extends PropertyAccessorElementImpl2
 
   @override
   GetterElement? get correspondingGetter2 =>
-      firstFragment.correspondingGetter2?.element;
+      firstFragment.variable2?.getter?.element;
 
   @override
   Element2 get enclosingElement2 => firstFragment.enclosingFragment.element;
@@ -10788,9 +10785,6 @@ class SetterFragmentImpl extends PropertyAccessorElementImpl
   @override
   PropertyAccessorElement? get correspondingGetter => variable2?.getter;
 
-  @override
-  GetterFragment? get correspondingGetter2 => variable2?.getter;
-
   @override
   PropertyAccessorElement? get correspondingSetter => null;