Fix a batch of DDC SDK compile errors.

sdk/lib/core/bool.dart

Index: sdk/lib/core/bool.dart
diff --git a/sdk/lib/core/bool.dart b/sdk/lib/core/bool.dart
index 3465527d7b067862d7524733b781845dab27326e..6660b76f58dda344090b716748eae77fbd900e9f 100644
--- a/sdk/lib/core/bool.dart
+++ b/sdk/lib/core/bool.dart
@@ -38,6 +38,12 @@ class bool {
    *
    *     const isLoggingOn = (const String.fromEnvironment("logging") == "on");
    */
+  // The .fromEnvironment() constructors are special in that we do not want
+  // users to call them using "new". We prohibit that by giving them bodies
+  // that throw, even though const constructors are not allowed to have bodies.
+  // Disable those static errors.
+  //ignore: const_constructor_with_body
+  //ignore: const_factory
   external const factory bool.fromEnvironment(String name,
       {bool defaultValue: false});