[PATCH] Add writeFileWithSystemEncoding to LibLLVMSupport

[Rafael Auler]

Rafael, I finished debugging our arabic test case. I tested a filename with the character 0xd6 and it worked OK just using regular cp 720. My initial command line test was failing because I was using "touch.exe" to create the file, and it was creating the file with the wrong name (the response file was OK, but the filename used a different character).

http://reviews.llvm.org/D4896