[parser] Simplify PreParser::ExpressionFromIdentifier

Change-Id: I2abd9ef9591a5e65dcb3fd0231c8d7467296b576
Reviewed-on: https://chromium-review.googlesource.com/c/1426127Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58990}

src/parsing/preparser.cc

@@ -410,14 +410,5 @@ bool PreParser::IdentifierEquals(const PreParserIdentifier& identifier,
   return identifier.string_ == other;
 }
 
-PreParserExpression PreParser::ExpressionFromIdentifier(
-    const PreParserIdentifier& name, int start_position, InferName infer) {
-  DCHECK_IMPLIES(name.string_ == nullptr, has_error());
-  if (name.string_ == nullptr) return PreParserExpression::Default();
-  VariableProxy* proxy =
-      expression_scope()->NewVariable(name.string_, start_position);
-  return PreParserExpression::FromIdentifier(name, proxy, zone());
-}
-
 }  // namespace internal
 }  // namespace v8

src/parsing/preparser.h

@@ -111,9 +111,7 @@ class PreParserExpression {
     return PreParserExpression(TypeField::encode(kSpreadExpression));
   }
 
-  static PreParserExpression FromIdentifier(const PreParserIdentifier& id,
-                                            VariableProxy* variable,
-                                            Zone* zone) {
+  static PreParserExpression FromIdentifier(const PreParserIdentifier& id) {
     return PreParserExpression(TypeField::encode(kIdentifierExpression) |
                                IdentifierTypeField::encode(id.type_));
   }
@@ -1567,7 +1565,12 @@ class PreParser : public ParserBase<PreParser> {
 
   PreParserExpression ExpressionFromIdentifier(
       const PreParserIdentifier& name, int start_position,
-      InferName infer = InferName::kYes);
+      InferName infer = InferName::kYes) {
+    if (name.string_ != nullptr) {
+      expression_scope()->NewVariable(name.string_, start_position);
+    }
+    return PreParserExpression::FromIdentifier(name);
+  }
 
   V8_INLINE Variable* DeclareCatchVariableName(
       Scope* scope, const PreParserIdentifier& identifier) {