ios,deps: remove private API symbols from openssl

Removes references for private APIs from openssl. The symbols
getcontext, setcontext, makecontext are not allowed in the iOS
App Store.

Author: jaimecbernardo

deps/openssl/config/opensslconf.h

@@ -17,6 +17,15 @@
 #ifndef OPENSSL_NO_HW_PADLOCK
 # define OPENSSL_NO_HW_PADLOCK
 #endif
+
+/* iOS app store won't allow getcontext, setcontext, makecontext */
+#if defined(__APPLE__) && defined(__MACH__)
+# include <TargetConditionals.h>
+# if defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE
+#  define OPENSSL_NO_ASYNC
+# endif
+#endif
+
 /* musl in Alpine Linux does not support getcontext etc.*/
 #if defined(OPENSSL_LINUX) && !defined(__GLIBC__) && !defined(__clang__)
 # define OPENSSL_NO_ASYNC