Serialize parameters visible ranges.

pkg/analyzer/lib/src/summary/summarize_ast.dart

Index: pkg/analyzer/lib/src/summary/summarize_ast.dart
diff --git a/pkg/analyzer/lib/src/summary/summarize_ast.dart b/pkg/analyzer/lib/src/summary/summarize_ast.dart
index 1c5081c710ca5dbc6b0548b8ed1b488ab5a57f77..29adbea6436ab54e7f269c8d25e6b0999350f6a9 100644
--- a/pkg/analyzer/lib/src/summary/summarize_ast.dart
+++ b/pkg/analyzer/lib/src/summary/summarize_ast.dart
@@ -544,6 +544,12 @@ class _SummarizeAstVisitor extends RecursiveAstVisitor {
   }
 
   void serializeFunctionBody(UnlinkedExecutableBuilder b, FunctionBody body) {
+    if (body is BlockFunctionBody || body is ExpressionFunctionBody) {
+      for (UnlinkedParamBuilder parameter in b.parameters) {
+        parameter.visibleOffset = body.offset;
+        parameter.visibleLength = body.length;
+      }
+    }
     List<UnlinkedExecutableBuilder> oldExecutables = executables;
     List<UnlinkedVariableBuilder> oldVariables = variables;
     executables = <UnlinkedExecutableBuilder>[];