[GIT-PULLS] [php-src] PR #23485: Fix GH-23459: Improve imagegrabscreen() performance on Windows

Pull Request: https://github.com/php/php-src/pull/23485
Author: LamentXU123

The original implementation of `imagegrabscreen` is super weird. It currently calls `GetPixel()` once for every pixel after capturing the desktop. On a 1560x1040 display, this results in more than 1.6 million GDI calls and takes around 3.2 seconds. (???)

This is a easy fix. Besides, I find a out-of-bound read in the original implementation. Anyways, now we retrieve the bitmap in a single `GetDIBits()` call as a top-down 32-bit DIB, then convert the returned RGBQUAD buffer directly into the GD true-color image.

I run the benchmark locally with a 1560×1040 pic.

Before: 2.997434s
After: 0.003682s

A 814x optimization in total.