LibJS: Don't store current token in both Lexer and Parser

Just give Parser a way to access the one stored in Lexer.

Author: awesomekling

Libraries/LibJS/Lexer.cpp

@@ -636,7 +636,7 @@ bool Lexer::slash_means_division() const
         || type == TokenType::TemplateLiteralEnd;
 }
 
-Token Lexer::next()
+Token const& Lexer::next()
 {
     auto trivia_start = m_position;
     auto in_template = !m_template_states.is_empty();
@@ -970,7 +970,7 @@ Token Lexer::next()
     return m_current_token;
 }
 
-Token Lexer::force_slash_as_regex()
+Token const& Lexer::force_slash_as_regex()
 {
     VERIFY(m_current_token.type() == TokenType::Slash || m_current_token.type() == TokenType::SlashEquals);
 

Libraries/LibJS/Lexer.h

@@ -19,15 +19,17 @@ class JS_API Lexer {
     explicit Lexer(StringView source, StringView filename = "(unknown)"sv, size_t line_number = 1, size_t line_column = 0);
     explicit Lexer(Utf16String source, StringView filename = "(unknown)"sv, size_t line_number = 1, size_t line_column = 0);
 
-    Token next();
+    // These both advance the lexer and return a reference to the current token.
+    Token const& next();
+    Token const& force_slash_as_regex();
+
+    [[nodiscard]] Token const& current_token() const { return m_current_token; }
 
     Utf16String const& source() const { return m_source; }
     String const& filename() const { return m_filename; }
 
     void disallow_html_comments() { m_allow_html_comments = false; }
 
-    Token force_slash_as_regex();
-
 private:
     void consume();
     bool consume_exponent();