tools/windows: update toolchain URL in MSYS build script

tools/windows/windows_install_prerequisites.sh

@@ -42,10 +42,11 @@ if [ -n "$IDF_PATH" ]; then
 fi
 
 # Automatically download precompiled toolchain, unpack at /opt/xtensa-esp32-elf/
-TOOLCHAIN_ZIP=xtensa-esp32-elf-win32-1.22.0-80-g6c4433a-5.2.0.zip
+TOOLCHAIN_ZIP=xtensa-esp32-elf-gcc8_2_0-esp32-2019r1-win32.zip
 echo "Downloading precompiled toolchain ${TOOLCHAIN_ZIP}..."
 cd ~
 curl -LO --retry 10 http://dl.espressif.com/dl/${TOOLCHAIN_ZIP}
+mkdir -p /opt
 cd /opt
 rm -rf /opt/xtensa-esp32-elf  # for upgrades
 unzip ~/${TOOLCHAIN_ZIP}