Revert "Add a hint on static uses of fuzzy arrows."

pkg/analyzer/lib/src/task/strong/checker.dart

Index: pkg/analyzer/lib/src/task/strong/checker.dart
diff --git a/pkg/analyzer/lib/src/task/strong/checker.dart b/pkg/analyzer/lib/src/task/strong/checker.dart
index e6e2b34f0dc0f66dcf6f1704bd0886e9806be61b..e09f6af3f3b8fec50d6c82c46e312c3ac9826b7d 100644
--- a/pkg/analyzer/lib/src/task/strong/checker.dart
+++ b/pkg/analyzer/lib/src/task/strong/checker.dart
@@ -772,8 +772,6 @@ class CodeChecker extends RecursiveAstVisitor {
       {DartType from, bool opAssign: false, bool isDeclarationCast: false}) {
     from ??= _getDefiniteType(expr);
 
-    _hintOnFuzzyArrows(expr, to, from: from);
-
     if (_needsImplicitCast(expr, to,
             from: from, isDeclarationCast: isDeclarationCast) ==
         true) {
@@ -1077,23 +1075,6 @@ class CodeChecker extends RecursiveAstVisitor {
     return rules.anyParameterType(ft, (pt) => pt.isDynamic);
   }
 
-  void _hintOnFuzzyArrows(Expression expr, DartType to, {DartType from}) {
-    from ??= _getDefiniteType(expr);
-
-    // If it is a subtype with fuzzy arrows on,
-    // check to see if it still is with them off.
-    if (rules.isSubtypeOf(from, to)) {
-      try {
-        rules.allowDynamicAsBottom = false;
-        // If still true, no warning needed
-        if (rules.isSubtypeOf(from, to)) return;
-        _recordMessage(expr, HintCode.USES_DYNAMIC_AS_BOTTOM, [from, to]);
-      } finally {
-        rules.allowDynamicAsBottom = true;
-      }
-    }
-  }
-
   /// Returns true if we need an implicit cast of [expr] from [from] type to
   /// [to] type, returns false if no cast is needed, and returns null if the
   /// types are statically incompatible.
@@ -1243,9 +1224,7 @@ class CodeChecker extends RecursiveAstVisitor {
         errorCode.name.startsWith('STRONG_MODE_TOP_LEVEL_')) {
       severity = ErrorSeverity.ERROR;
     }
-    if (severity != ErrorSeverity.INFO ||
-        _options.strongModeHints ||
-        errorCode == HintCode.USES_DYNAMIC_AS_BOTTOM) {
+    if (severity != ErrorSeverity.INFO || _options.strongModeHints) {
       int begin = node is AnnotatedNode
           ? node.firstTokenAfterCommentAndMetadata.offset
           : node.offset;