on both the mac and linux, /usr/local/include is treated 
as a "C++ Friendly" system header directory.  This fixes
PR6523.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97885 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/InitHeaderSearch.cpp b/lib/Frontend/InitHeaderSearch.cpp
index 4f972f0..cd749d2 100644
--- a/lib/Frontend/InitHeaderSearch.cpp
+++ b/lib/Frontend/InitHeaderSearch.cpp
@@ -436,7 +436,7 @@
     break;
   }
 
-  AddPath("/usr/local/include", System, false, false, false);
+  AddPath("/usr/local/include", System, true, false, false);
   AddPath("/usr/include", System, false, false, false);
 }