Build/Windows: Update the Windows icon as svg and build derivatives from it

win32/build/mkico.bat

@@ -0,0 +1,8 @@
+@echo off
+magick php.svg -size 512x512 php.bmp
+
+for %%i in (16,24,32,48,64,128,256) do magick php.bmp -scale %%ix%%i php-ico-%%i.png
+
+magick -adjoin php-ico-* php.ico
+
+del /f /q php-ico-*.png php.bmp

win32/build/mkico.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+convert php.svg -size 512x512  php.bmp
+
+for I in 16 24 32 48 64 128 256;
+do
+    convert php.bmp -scale ${I}x${I} php-ico-${I}.png;
+done
+
+convert -adjoin php-ico-* php.ico
+
+rm -f php-ico-*.png php.bmp