Add --no-declaration-casts option to analyzer.

pkg/analyzer/lib/src/context/context.dart

Index: pkg/analyzer/lib/src/context/context.dart
diff --git a/pkg/analyzer/lib/src/context/context.dart b/pkg/analyzer/lib/src/context/context.dart
index 7d85e944af89097ab08678ce700f99a400469857..9285f76ed75767e6cc0e60d45ff589ec53293893 100644
--- a/pkg/analyzer/lib/src/context/context.dart
+++ b/pkg/analyzer/lib/src/context/context.dart
@@ -285,6 +285,9 @@ class AnalysisContextImpl implements InternalAnalysisContext {
             ? this._options.strongModeHints != options.strongModeHints
             : false) ||
         ((options is AnalysisOptionsImpl)
+            ? this._options.declarationCasts != options.declarationCasts
+            : false) ||
+        ((options is AnalysisOptionsImpl)
             ? this._options.implicitCasts != options.implicitCasts
             : false) ||
         ((options is AnalysisOptionsImpl)
@@ -323,6 +326,7 @@ class AnalysisContextImpl implements InternalAnalysisContext {
     this._options.patchPaths = options.patchPaths;
     if (options is AnalysisOptionsImpl) {
       this._options.strongModeHints = options.strongModeHints;
+      this._options.declarationCasts = options.declarationCasts;
       this._options.implicitCasts = options.implicitCasts;
       this._options.nonnullableTypes = options.nonnullableTypes;
       this._options.implicitDynamic = options.implicitDynamic;