fix for build failures resulting from "string ops for i386" change

libc/string/memcpy.c

@@ -10,6 +10,7 @@
 #ifdef WANT_WIDE
 # define Wmemcpy wmemcpy
 #else
+# undef memcpy
 # define Wmemcpy memcpy
 #endif
 

libc/string/memset.c

@@ -10,7 +10,7 @@
 #ifdef WANT_WIDE
 # define Wmemset wmemset
 #else
-/* Experimentally off - libc_hidden_proto(memset) */
+# undef memset
 # define Wmemset memset
 #endif