always search for "builtin" headers at the end of the search path,
and never remap them with -isysroot.  This fixes PR3614.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65012 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Driver/clang.cpp b/Driver/clang.cpp
index a818c8d..79166fb 100644
--- a/Driver/clang.cpp
+++ b/Driver/clang.cpp
@@ -1098,8 +1098,8 @@
     MainExecutablePath.eraseComponent();  // Remove /clang from foo/bin/clang
     MainExecutablePath.eraseComponent();  // Remove /bin   from foo/bin
     MainExecutablePath.appendComponent("Headers"); // Get foo/Headers
-    Init.AddPath(MainExecutablePath.c_str(), InitHeaderSearch::System,
-        false, false, false);
+    Init.AddPath(MainExecutablePath.c_str(), InitHeaderSearch::After,
+                 false, false, false);
   }
   
   if (!nostdinc)