Holger Arnold:  Correct the use and testing of __GNUC__ and __GNUC_MINOR__ in <__config>.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@165151 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CREDITS.TXT b/CREDITS.TXT
index ba68315..336edde 100644
--- a/CREDITS.TXT
+++ b/CREDITS.TXT
@@ -66,3 +66,7 @@
 N: Dimitry Andric
 E: dimitry@andric.com
 D: Visibility fixes, minor FreeBSD portability patches.
+
+N: Holger Arnold
+E: holgerar@gmail.com
+D: Minor fix.