Rename setters VariableElementImpl.[const3, final2] to isConst and isFinal.

pkg/analyzer/lib/src/summary/resynthesize.dart

Index: pkg/analyzer/lib/src/summary/resynthesize.dart
diff --git a/pkg/analyzer/lib/src/summary/resynthesize.dart b/pkg/analyzer/lib/src/summary/resynthesize.dart
index d8f0ce26e61bea9e5a86c32927239df42d8c785b..c95f67f98e9056a84acf82f684b01758eb39835e 100644
--- a/pkg/analyzer/lib/src/summary/resynthesize.dart
+++ b/pkg/analyzer/lib/src/summary/resynthesize.dart
@@ -1645,9 +1645,9 @@ class _UnitResynthesizer {
           implicitVariables[name] = variable;
           accessorsData.implicitVariables.add(variable);
           variable.synthetic = true;
-          variable.final2 = kind == UnlinkedExecutableKind.getter;
+          variable.isFinal = kind == UnlinkedExecutableKind.getter;
         } else {
-          variable.final2 = false;
+          variable.isFinal = false;
         }
         accessor.variable = variable;
         // link