GDScript: Track columns by raw string offsets

modules/gdscript/gdscript_tokenizer_buffer.cpp

@@ -447,6 +447,8 @@ GDScriptTokenizer::Token GDScriptTokenizerBuffer::scan() {
 		}
 		Token eof;
 		eof.type = Token::TK_EOF;
+		eof.start_line = current_line;
+		eof.end_line = current_line;
 		return eof;
 	};