Split the JSON output into multiple lines.

pkg/analyzer/lib/src/generated/error.dart

Index: pkg/analyzer/lib/src/generated/error.dart
diff --git a/pkg/analyzer/lib/src/generated/error.dart b/pkg/analyzer/lib/src/generated/error.dart
index 80c7e0535c09a53e6eec72b42c76f370f61ac4eb..6c89003be564c418152b572ce0ffee74666e7c0f 100644
--- a/pkg/analyzer/lib/src/generated/error.dart
+++ b/pkg/analyzer/lib/src/generated/error.dart
@@ -2222,8 +2222,7 @@ class CompileTimeErrorCode extends ErrorCode {
    * <i>rethrow;</i> is not enclosed within a on-catch clause.
    */
   static const CompileTimeErrorCode RETHROW_OUTSIDE_CATCH =
-      const CompileTimeErrorCode(
-          'RETHROW_OUTSIDE_CATCH', "rethrow must be inside of a catch clause");
+      shared_messages.RETHROW_OUTSIDE_CATCH;
 
   /**
    * 13.12 Return: It is a compile-time error if a return statement of the form