Add Michael van der Westhuizen to CREDITS.TXT

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@174732 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CREDITS.TXT b/CREDITS.TXT
index 544138d..5294851 100644
--- a/CREDITS.TXT
+++ b/CREDITS.TXT
@@ -74,6 +74,9 @@
 N: Richard Smith
 D: Minor patches.
 
+N: Michael van der Westhuizen
+E: r1mikey at gmail dot com
+
 N: Klaas de Vries
 E: klaas at klaasgaaf dot nl
 D: Minor bug fix.