[parser] Hide expression classifiers in parser implementation

src/parsing/expression-classifier.h

Index: src/parsing/expression-classifier.h
diff --git a/src/parsing/expression-classifier.h b/src/parsing/expression-classifier.h
index f1c2d3a23969e07b1d47e503349aa46fc450b0e9..01141d4188eab8429572b58970837f598976a6e9 100644
--- a/src/parsing/expression-classifier.h
+++ b/src/parsing/expression-classifier.h
@@ -357,20 +357,6 @@ class ExpressionClassifier {
         reported_errors_end_;
   }
 
-  // Accumulate errors that can be arbitrarily deep in an expression.
-  // These correspond to the ECMAScript spec's 'Contains' operation
-  // on productions. This includes:
-  //
-  // - YieldExpression is disallowed in arrow parameters in a generator.
-  // - AwaitExpression is disallowed in arrow parameters in an async function.
-  // - AwaitExpression is disallowed in async arrow parameters.
-  //
-  V8_INLINE void AccumulateFormalParameterContainmentErrors(
-      ExpressionClassifier* inner) {
-    Accumulate(inner, FormalParameterInitializerProduction |
-                          AsyncArrowFormalParametersProduction);
-  }
-
   V8_INLINE int GetNonPatternBegin() const { return non_pattern_begin_; }
 
   V8_INLINE void Discard() {