Convert FOR_IN_WITH_CONST_VARIABLE to using message.

Analyzer reports it, so it should not be fromFasta().

R=brianwilkerson@google.com

Change-Id: Id0db50e5f770bbae60d1955a05e632f548a104e3
Reviewed-on: https://dart-review.googlesource.com/72140
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/analyzer/lib/src/error/codes.dart b/pkg/analyzer/lib/src/error/codes.dart
index 4ca91e6..a38ea7e 100644
--- a/pkg/analyzer/lib/src/error/codes.dart
+++ b/pkg/analyzer/lib/src/error/codes.dart
@@ -2498,7 +2498,10 @@
               ' of the larger declaration signature');
 
   static const CompileTimeErrorCode FOR_IN_WITH_CONST_VARIABLE =
-      const CompileTimeErrorCode.fromFasta('FOR_IN_WITH_CONST_VARIABLE');
+      const CompileTimeErrorCode('FOR_IN_WITH_CONST_VARIABLE',
+          "A for-in loop-variable can't be 'const'.",
+          correction: "Try removing the 'const' modifier from the variable, or "
+              "use a different variable.");
 
   /**
    * It is a compile-time error if a generic function type is used as an actual