Added the ExecWait() function.

llvm-svn: 8578
diff --git a/llvm/include/Support/SystemUtils.h b/llvm/include/Support/SystemUtils.h
index 4573e27..7a4c627 100644
--- a/llvm/include/Support/SystemUtils.h
+++ b/llvm/include/Support/SystemUtils.h
@@ -34,4 +34,12 @@
 			  const std::string &StdOutFile = "",
 			  const std::string &StdErrFile = "");
 
+///
+/// Function: ExecWait()
+///
+/// Description:
+///  Execute a program with the given arguments and environment and 
+///  wait for it to terminate.
+///
+int ExecWait (char ** argv, char ** envp);
 #endif