fix #26782, add no-implicit-casts, no-implicit-dynamic options

pkg/analyzer_cli/lib/src/options.dart

Index: pkg/analyzer_cli/lib/src/options.dart
diff --git a/pkg/analyzer_cli/lib/src/options.dart b/pkg/analyzer_cli/lib/src/options.dart
index 3706464c41c3469e8328a3bd67f4ca88ac8f9c48..030f1bfec653a3fa11b4fbc2ecd796ae27a1538a 100644
--- a/pkg/analyzer_cli/lib/src/options.dart
+++ b/pkg/analyzer_cli/lib/src/options.dart
@@ -150,6 +150,12 @@ class CommandLineOptions {
   /// Whether to use strong static checking.
   final bool strongMode;
 
+  /// Whether implicit casts are enabled (in strong mode)
+  final bool implicitCasts;
+
+  /// Whether implicit dynamic is enabled (mainly for strong mode users)
+  final bool implicitDynamic;
+
   /// Whether to treat lints as fatal
   final bool lintsAreFatal;
 
@@ -197,6 +203,8 @@ class CommandLineOptions {
         sourceFiles = args.rest,
         warningsAreFatal = args['fatal-warnings'],
         strongMode = args['strong'],
+        implicitCasts = !args['no-implicit-casts'],
+        implicitDynamic = !args['no-implicit-dynamic'],
         lintsAreFatal = args['fatal-lints'];
 
   /// Parse [args] into [CommandLineOptions] describing the specified
@@ -478,7 +486,13 @@ class CommandLineOptions {
           negatable: false,
           hide: true)
       ..addFlag('strong',
-          help: 'Enable strong static checks (https://goo.gl/DqcBsw)');
+          help: 'Enable strong static checks (https://goo.gl/DqcBsw)')
+      ..addFlag('no-implicit-casts',
+          negatable: false,
+          help: 'Disable implicit casts in strong mode (https://goo.gl/cTLz40)')
+      ..addFlag('no-implicit-dynamic',
+          negatable: false,
+          help: 'Disable implicit dynamic (https://goo.gl/m0UgXD)');
 
     try {
       // TODO(scheglov) https://code.google.com/p/dart/issues/detail?id=11061