Add bench-final.php helper for multi-config parser benchmarking

Reports best/median/average QPS over N runs with the currently-loaded
PHP interpreter configuration. Used to measure the effect of the
interpreter changes on top of opcache and tracing JIT configurations.

Author: JanJakes

packages/mysql-on-sqlite/tests/tools/bench-final.php

@@ -0,0 +1,61 @@
+<?php
+/**
+ * Final multi-config benchmark for the parser exploration.
+ */
+
+set_error_handler(
+	function ( $s, $m, $f, $l ) {
+		throw new ErrorException( $m, 0, $s, $f, $l );
+	}
+);
+
+require_once __DIR__ . '/../../src/parser/class-wp-parser-grammar.php';
+require_once __DIR__ . '/../../src/parser/class-wp-parser-node.php';
+require_once __DIR__ . '/../../src/parser/class-wp-parser-token.php';
+require_once __DIR__ . '/../../src/parser/class-wp-parser.php';
+require_once __DIR__ . '/../../src/mysql/class-wp-mysql-token.php';
+require_once __DIR__ . '/../../src/mysql/class-wp-mysql-lexer.php';
+require_once __DIR__ . '/../../src/mysql/class-wp-mysql-parser.php';
+
+$runs = (int) ( $argv[1] ?? 10 );
+
+$grammar = new WP_Parser_Grammar( require __DIR__ . '/../../src/mysql/mysql-grammar.php' );
+$handle  = fopen( __DIR__ . '/../mysql/data/mysql-server-tests-queries.csv', 'r' );
+$queries = array();
+$header  = true;
+while ( ( $r = fgetcsv( $handle, null, ',', '"', '\\' ) ) !== false ) {
+	if ( $header ) {
+		$header = false;
+		continue; }
+	if ( null !== $r[0] ) {
+		$queries[] = $r[0];
+	}
+}
+fclose( $handle );
+
+$all_tokens = array();
+foreach ( $queries as $q ) {
+	$all_tokens[] = ( new WP_MySQL_Lexer( $q ) )->remaining_tokens();
+}
+$count = count( $queries );
+printf( "Loaded %d queries\n", $count );
+
+$durations = array();
+for ( $i = 0; $i < $runs; $i++ ) {
+	$start = microtime( true );
+	$fail  = 0;
+	foreach ( $all_tokens as $t ) {
+		if ( null === ( new WP_MySQL_Parser( $grammar, $t ) )->parse() ) {
+			++$fail;
+		}
+	}
+	$d           = microtime( true ) - $start;
+	$durations[] = $d;
+}
+sort( $durations );
+$best = $durations[0];
+$med  = $durations[ (int) ( count( $durations ) / 2 ) ];
+$avg  = array_sum( $durations ) / count( $durations );
+printf( "best %.4fs  %6d QPS\n", $best, $count / $best );
+printf( "med  %.4fs  %6d QPS\n", $med, $count / $med );
+printf( "avg  %.4fs  %6d QPS\n", $avg, $count / $avg );