Set 'isSyntheticDefault' for default constructors.

pkg/front_end/testcases/inference/infer_field_overrides_getter.dart.strong.expect

Index: pkg/front_end/testcases/inference/infer_field_overrides_getter.dart.strong.expect
diff --git a/pkg/front_end/testcases/inference/infer_field_overrides_getter.dart.strong.expect b/pkg/front_end/testcases/inference/infer_field_overrides_getter.dart.strong.expect
index 4648fde440ad2c416cf76fa43ead038eb6dbeb70..e0b83866c071f167c801476215a53e0e7d8ce6b6 100644
--- a/pkg/front_end/testcases/inference/infer_field_overrides_getter.dart.strong.expect
+++ b/pkg/front_end/testcases/inference/infer_field_overrides_getter.dart.strong.expect
@@ -3,13 +3,13 @@ import self as self;
 import "dart:core" as core;
 
 abstract class A extends core::Object {
-  constructor •() → void
+  default constructor •() → void
     : super core::Object::•()
     ;
   abstract get x() → core::int;
 }
 class B extends core::Object {
-  constructor •() → void
+  default constructor •() → void
     : super core::Object::•()
     ;
   get x() → core::int
@@ -17,25 +17,25 @@ class B extends core::Object {
 }
 class C extends self::A {
   field core::int x = null;
-  constructor •() → void
+  default constructor •() → void
     : super self::A::•()
     ;
 }
 class D extends self::B {
   field core::int x = null;
-  constructor •() → void
+  default constructor •() → void
     : super self::B::•()
     ;
 }
 class E extends core::Object implements self::A {
   field core::int x = null;
-  constructor •() → void
+  default constructor •() → void
     : super core::Object::•()
     ;
 }
 class F extends core::Object implements self::B {
   field core::int x = null;
-  constructor •() → void
+  default constructor •() → void
     : super core::Object::•()
     ;
 }
@@ -43,7 +43,7 @@ abstract class Object&B = core::Object with self::B {
 }
 class G extends self::Object&B {
   field core::int x = null;
-  constructor •() → void
+  default constructor •() → void
     : super core::Object::•()
     ;
 }