Add hasPublishedDocs to every diagnostic code

This makes it easier for me to find diagnostics that still need to be
documented because I can search for 'hasPublishedDocs: false'. It's
hard to search for places where it isn't specified.

In case you're interested, we currently have documentation for 70% of
the diagnostics represented in this file.

In almost every case the value is `false`, but there are two codes whose
documentation has already been published but which were not marked as
such. This means that we weren't associating a URL with the diagnostic,
but that's now been fixed.

Change-Id: I4e17671e319ec8e8887aacb6758594d7962bfc85
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/429202
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>

Author: bwilkerson

pkg/analyzer/lib/src/error/codes.g.dart

@@ -4582,6 +4582,7 @@ class CompileTimeErrorCode extends DiagnosticCode {
         hasPublishedDocs: true,
       );
 
+  ///  The documentation is in `front_end/message.yaml`.
   static const CompileTimeErrorCode
   RECORD_LITERAL_ONE_POSITIONAL_NO_TRAILING_COMMA = CompileTimeErrorCode(
     'RECORD_LITERAL_ONE_POSITIONAL_NO_TRAILING_COMMA',
@@ -7032,6 +7033,7 @@ class WarningCode extends DiagnosticCode {
     'INVALID_WIDGET_PREVIEW_APPLICATION',
     "The '@Preview(...)' annotation can only be applied to public, statically "
         "accessible constructors and functions.",
+    hasPublishedDocs: true,
   );
 
   ///  Parameters:
@@ -7043,6 +7045,7 @@ class WarningCode extends DiagnosticCode {
     "'@Preview(...)' can only accept arguments that consist of literals and "
         "public symbols.",
     correctionMessage: "Rename private symbol '{0}' to '{1}'.",
+    hasPublishedDocs: true,
   );
 
   ///  Parameters: