[RFC] Writing a document for cross compilation by using LLVM/Clang

Hi all,

  I see people regularly ask questions about cross compiling on LLVM ML [1][2].
I think we need a place to collect those information, either on LLVM or Clang
website. What do you think?

Regards,
chenwj

[1] http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-June/050759.html
[2] http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-July/052149.html
[3] http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-July/051426.html