Return only the least significant 8 bits of the exit status from
Process::Wait on Windows (mimicing POSIX behaviour).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143876 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Windows/Program.inc b/lib/Support/Windows/Program.inc
index e486e6e..7e38168 100644
--- a/lib/Support/Windows/Program.inc
+++ b/lib/Support/Windows/Program.inc
@@ -367,7 +367,7 @@
     return -2;
   }
 
-  return status;
+  return status & 0377;
 }
 
 bool