Add type inference for super property gets.

pkg/front_end/lib/src/fasta/kernel/frontend_accessors.dart

Index: pkg/front_end/lib/src/fasta/kernel/frontend_accessors.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/frontend_accessors.dart b/pkg/front_end/lib/src/fasta/kernel/frontend_accessors.dart
index 27ba25d99fe7e232857124c8c715c6a5b69fb81e..e06bbc7d3c64242aa549c5e75875a9cc3f50e0d4 100644
--- a/pkg/front_end/lib/src/fasta/kernel/frontend_accessors.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/frontend_accessors.dart
@@ -14,6 +14,7 @@ import 'package:front_end/src/fasta/kernel/kernel_shadow_ast.dart'
         KernelNullAwarePropertyGet,
         KernelPropertyAssign,
         KernelPropertyGet,
+        KernelSuperPropertyGet,
         KernelThisExpression,
         KernelVariableDeclaration,
         KernelVariableGet;
@@ -374,7 +375,7 @@ class SuperPropertyAccessor extends Accessor {
   Expression _makeRead(KernelComplexAssignment complexAssignment) {
     if (getter == null) return makeInvalidRead();
     // TODO(ahe): Use [DirectPropertyGet] when possible.
-    var read = new SuperPropertyGet(name, getter)
+    var read = new KernelSuperPropertyGet(name, getter)
       ..fileOffset = offsetForToken(token);
     complexAssignment?.read = read;
     return read;