[PATCH] Add writeFileWithSystemEncoding to LibLLVMSupport

[Rafael Auler]

Thanks for your suggestions, I will submit a revised patch soon. Rafael, regarding your comment, I didn't add a table, but I did add a comment describing which encoding each tool use in the clang-side of the patch at http://reviews.llvm.org/D4897, file include/clang/Driver/Tool.h. However, if you want, I can add the table here too. What do you think?

http://reviews.llvm.org/D4896