[parser] Reuse expression classifier across conditional lhs/rhs

Change-Id: Ibf0ee76cc19799be405f45bcba7a1d3a7c5c4d38
Reviewed-on: https://chromium-review.googlesource.com/c/1288390
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56786}

src/parsing/parser-base.h

@@ -2966,27 +2966,26 @@ ParserBase<Impl>::ParseConditionalContinuation(ExpressionT expression,
   BindingPatternUnexpectedToken();
   ArrowFormalParametersUnexpectedToken();
 
+  ExpressionClassifier classifier(this);
+
   ExpressionT left;
   {
     SourceRangeScope range_scope(scanner(), &then_range);
     Consume(Token::CONDITIONAL);
-    ExpressionClassifier classifier(this);
     // In parsing the first assignment expression in conditional
     // expressions we always accept the 'in' keyword; see ECMA-262,
     // section 11.12, page 58.
     left = ParseAssignmentExpression(true, CHECK_OK);
-    AccumulateNonBindingPatternErrors();
   }
   ExpressionT right;
   {
     SourceRangeScope range_scope(scanner(), &else_range);
     Expect(Token::COLON, CHECK_OK);
-    ExpressionClassifier classifier(this);
     right = ParseAssignmentExpression(accept_IN, CHECK_OK);
-    AccumulateNonBindingPatternErrors();
   }
   ExpressionT expr = factory()->NewConditional(expression, left, right, pos);
   impl()->RecordConditionalSourceRange(expr, then_range, else_range);
+  AccumulateNonBindingPatternErrors();
   return expr;
 }