Introduces "--initializing-formal-access".

pkg/compiler/lib/src/compile_time_constants.dart

Index: pkg/compiler/lib/src/compile_time_constants.dart
diff --git a/pkg/compiler/lib/src/compile_time_constants.dart b/pkg/compiler/lib/src/compile_time_constants.dart
index 9bab3a5f51368b109edcb5962d8032a682c56d44..e5626dc5196b7d9f7db2c22a1f9c7c3518ed1537 100644
--- a/pkg/compiler/lib/src/compile_time_constants.dart
+++ b/pkg/compiler/lib/src/compile_time_constants.dart
@@ -1182,6 +1182,9 @@ class ConstructorEvaluator extends CompileTimeConstantEvaluator {
       if (parameter.isInitializingFormal) {
         InitializingFormalElement initializingFormal = parameter;
         updateFieldValue(node, initializingFormal.fieldElement, argument);
+        if (compiler.options.enableInitializingFormalAccess) {
+          definitions[parameter] = argument;
+        }
       } else {
         potentiallyCheckType(parameter, argument);
         definitions[parameter] = argument;