Handle use of fromEnvironment from serialized data.

pkg/compiler/lib/src/elements/elements.dart

Index: pkg/compiler/lib/src/elements/elements.dart
diff --git a/pkg/compiler/lib/src/elements/elements.dart b/pkg/compiler/lib/src/elements/elements.dart
index 2e1525c640df5d89d95ab284f4c612e71ee1b921..9b12bed4b5c088eeb369167edcfff9c135e497c6 100644
--- a/pkg/compiler/lib/src/elements/elements.dart
+++ b/pkg/compiler/lib/src/elements/elements.dart
@@ -1324,6 +1324,15 @@ abstract class ConstructorElement extends FunctionElement
   /// `int.fromEnvironment`, or `String.fromEnvironment`.
   bool get isFromEnvironmentConstructor;
 
+  /// `true` if this constructor is `int.fromEnvironment`.
+  bool get isIntFromEnvironmentConstructor;
+
+  /// `true` if this constructor is `bool.fromEnvironment`.
+  bool get isBoolFromEnvironmentConstructor;
+
+  /// `true` if this constructor is `String.fromEnvironment`.
+  bool get isStringFromEnvironmentConstructor;
+
   /// Use [enclosingClass] instead.
   @deprecated
   get enclosingElement;