Adds support for building Mandrel on Windows

- Windows support
- zip archive support for both Linux and Windows

Building on Winows
------------------

* Installed Visual Studio (C/C++ support)
* Installed Python 2.7 and on PATH  (de facto mx requirements)
* Downloaded OpenJDK
* git et co., e.g. from https://github.com/cmderdev/cmder/releases/download/v1.3.16/cmder.zip
* Have on PATH: C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build
Then:
```
set PYTHONHTTPSVERIFY=0
vcvarsall.bat x86_amd64
set JAVA_HOME=C:\projects\openjdk-11.0.9_11\
set PATH=%JAVA_HOME%\bin;%PATH%
set MAVEN_REPO=C:/projects/.m2
set MANDREL_REPO=C:/projects/graal/graal
set MX_HOME=C:/projects/graal/mx
set MANDREL_HOME=C:/projects/graal/mandrel-java11-windows-amd64-20.2-SNAPSHOT
%JAVA_HOME%/bin/java -ea build.java --maven-local-repository %MAVEN_REPO% --mandrel-repo %MANDREL_REPO% --mx-home %MX_HOME% --mandrel-version 20.2-SNAPSHOT --mandrel-home %MANDREL_HOME% --archive-suffix zip --verbose
```