Bugpoint was not correctly capturing stderr!  This caused it to "find" bugs
that didn't exist, missing the ones that do :(


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12978 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/SystemUtils.cpp b/lib/Support/SystemUtils.cpp
index dafbf98..a39c5ab 100644
--- a/lib/Support/SystemUtils.cpp
+++ b/lib/Support/SystemUtils.cpp
@@ -142,7 +142,10 @@
   case 0:               // Child
     RedirectFD(StdInFile, 0);      // Redirect file descriptors...
     RedirectFD(StdOutFile, 1);
-    RedirectFD(StdErrFile, 2);
+    if (StdOutFile != StdErrFile)
+      RedirectFD(StdErrFile, 2);
+    else
+      dup2(1, 2);
 
     execv(ProgramPath.c_str(), (char *const *)Args);
     std::cerr << "Error executing program: '" << ProgramPath;