Remove the program class.

It was only used to implement ExecuteAndWait and ExecuteNoWait. Expose just
those two functions and make Execute and Wait implementations details.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183864 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/DataStream.cpp

@@ -66,7 +66,7 @@ public:
   error_code OpenFile(const std::string &Filename) {
     if (Filename == "-") {
       Fd = 0;
-      sys::Program::ChangeStdinToBinary();
+      sys::ChangeStdinToBinary();
       return error_code::success();
     }