[pkg/js_shared] address a few analysis issues

Change-Id: I9ce9c66fa24bf58172b0fb2545c8bd745bc2fe68
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/249549
Reviewed-by: Nicholas Shahan <[email protected]>
Commit-Queue: Devon Carew <[email protected]>

Author: devoncarew

pkg/js_shared/analysis_options.yaml

@@ -0,0 +1 @@
+include: package:lints/core.yaml

pkg/js_shared/lib/synced/recipe_syntax.dart

@@ -131,7 +131,9 @@ abstract class Recipe {
   static const int _at = 0x40;
   static const String _atString = '@';
 
+  // ignore: unused_field
   static const int _uppercaseA = 0x41;
+  // ignore: unused_field
   static const int _uppercaseZ = 0x5A;
 
   static const int _leftBracket = 0x5B;
@@ -148,6 +150,7 @@ abstract class Recipe {
   static const String _backtickString = '`';
 
   static const int _lowercaseA = 0x61;
+  // ignore: unused_field
   static const int _lowercaseZ = 0x7A;
 
   static const int _leftBrace = 0x7B;

pkg/js_shared/pubspec.yaml

@@ -9,3 +9,4 @@ environment:
 dev_dependencies:
   _fe_analyzer_shared: any
   expect: any
+  lints: any

sdk/lib/_internal/js_shared/lib/synced/recipe_syntax.dart

@@ -131,7 +131,9 @@ abstract class Recipe {
   static const int _at = 0x40;
   static const String _atString = '@';
 
+  // ignore: unused_field
   static const int _uppercaseA = 0x41;
+  // ignore: unused_field
   static const int _uppercaseZ = 0x5A;
 
   static const int _leftBracket = 0x5B;
@@ -148,6 +150,7 @@ abstract class Recipe {
   static const String _backtickString = '`';
 
   static const int _lowercaseA = 0x61;
+  // ignore: unused_field
   static const int _lowercaseZ = 0x7A;
 
   static const int _leftBrace = 0x7B;