modern objc translator: string.h is unavailable on some non-OSX
platforms declare memset in rewritten code instead.

llvm-svn: 159454
diff --git a/clang/lib/Rewrite/RewriteModernObjC.cpp b/clang/lib/Rewrite/RewriteModernObjC.cpp
index b0f4c0d..a14a9ef 100644
--- a/clang/lib/Rewrite/RewriteModernObjC.cpp
+++ b/clang/lib/Rewrite/RewriteModernObjC.cpp
@@ -5958,7 +5958,7 @@
   }
   
   // needed for use of memset.
-  Preamble += "\n#include <string.h>\n";
+  Preamble += "\nextern \"C\" void * memset(void *b, int c, unsigned long len);\n";
   
   // Declarations required for modern objective-c array and dictionary literals.
   Preamble += "\n#include <stdarg.h>\n";