Add reliable way to detect multi-config generators
`CMAKE_NO_BUILD_TYPE` is only defined when generating Visual Studio projects targeting Windows platform. It means it is **not** defined when generating Xcode projects or VS projects targeting Android Tegra (or any proprietary platform).
This variable is defined in [Windows-MSVC.cmake](https://gitlab.kitware.com/cmake/cmake/blob/master/Modules/Platform/Windows-MSVC.cmake#L41) :
```
if(NOT CMAKE_NO_BUILD_TYPE AND CMAKE_GENERATOR MATCHES "Visual Studio")
set (CMAKE_NO_BUILD_TYPE 1)
endif()
```
I think this should not be in a platform specific file.
issue