Cross platform build is broken on Windows

[eres-j]

Hi,

I try to build luajit for Android on Windows but fall into this issue: WohlSoft/LuaJIT#22
This the first error I got:

[3/79] Generating luajit.h
FAILED: luajit.h C:/Dev/github/eres-j/luajit-cmake/build/luajit.h
C:\WINDOWS\system32\cmd.exe /C "cd /D C:\Dev\github\eres-j\luajit-cmake\build && C:\Dev\github\eres-j\luajit-cmake\build\minilua\minilua C:/Dev/github/eres-j/glsandbox/ext/LuaJIT/LuaJIT/src/host/genversion.lua C:/Dev/github/eres-j/glsandbox/ext/LuaJIT/LuaJIT/src/luajit_rolling.h C:/Dev/github/eres-j/luajit-cmake/build/luajit_relver.txt C:/Dev/github/eres-j/luajit-cmake/build/luajit.h"
'C:\Dev\github\eres-j\luajit-cmake\build\minilua\minilua' n'est pas reconnu en tant que commande interne
ou externe, un programme exécutable ou un fichier de commandes.
ninja: build stopped: subcommand failed.

I cherry picked relevant changes:
WohlSoft/LuaJIT@5c4ccfa
WohlSoft/LuaJIT@c46d53e
and it works :)

Step to reproduce:

"%ProgramFiles%\CMake\bin\cmake.exe" -B build -G "Ninja" -DLUAJIT_DIR="C:/Dev/github/LuaJIT/LuaJIT" -DCMAKE_TOOLCHAIN_FILE=C:/Dev/Android/android-sdk/ndk/26.1.10909125/build/cmake/android.toolchain.cmake -DCMAKE_SYSTEM_NAME=Android -DCMAKE_SYSTEM_VERSION=21 -DCMAKE_ANDROID_ARCH_ABI=arm64-v8a -DCMAKE_ANDROID_NDK=C:/Dev/Android/android-sdk/ndk/26.1.10909125 -DCMAKE_ANDROID_NDK_TOOLCHAIN_VERSION=clang -DCMAKE_ANDROID_STL_TYPE=c++_static -DCMAKE_BUILD_TYPE=Debug -DANDROID_PLATFORM=21 -DANDROID_ABI=arm64-v8a -DLUAJIT_BUILD_EXE=FALSE
"%ProgramFiles%\CMake\bin\cmake.exe" --build "build" --config Debug

I'm going to make a pull request.