[LLVMdev] Using thin archives when building llvm

[Rafael Espíndola]

> CMake has undocumented variables set by the Modules/Platform/*
> files to specify the rules for creating archives.  These are:
>
>  CMAKE_<LANG>_ARCHIVE_{CREATE,APPEND,FINISH}
>
> for creating, appending to, and finishing an archive.  For
> tools/platforms that do not support separate steps we also
> have:
>
>  CMAKE_<LANG>_CREATE_STATIC_LIBRARY

Setting CMAKE_CXX_CREATE_STATIC_LIBRARY works on OS X and linux, but
on windows I still see a call to "lld-link2 /lib..." when
CMAKE_CXX_CREATE_STATIC_LIBRARY is set to use llvm-lib.

Cheers,
Rafael