iOS: detect and avoid net/route.h

LWS builds OK on iOS SDK as unix type plat, except it
doesn't have net/route.h.

Detect we're building on iOS at CMake and export a
preprocessor define we can use to snip out the missing
include.

CMakeLists.txt

@@ -179,6 +179,10 @@ option(LWS_WITH_FANALYZER "Enable gcc -fanalyzer if compiler supports" OFF)
 # End of user settings
 #
 
+if(IOS)
+    set(LWS_DETECTED_PLAT_IOS 1)
+endif()
+
 # Workaround for ESP-IDF
 # Detect ESP_PLATFORM environment flag, if exist, set LWS_WITH_ESP32.
 # Otherwise the user may not be able to run configuration ESP-IDF in the first time.

cmake/lws_config.h.in

@@ -24,6 +24,7 @@
 #cmakedefine LWS_BUILD_HASH "${LWS_BUILD_HASH}"
 #cmakedefine LWS_BUILTIN_GETIFADDRS
 #cmakedefine LWS_CLIENT_HTTP_PROXYING
+#cmakedefine LWS_DETECTED_PLAT_IOS
 #cmakedefine LWS_FALLBACK_GETHOSTBYNAME
 #cmakedefine LWS_HAS_INTPTR_T
 #cmakedefine LWS_HAS_GETOPT_LONG

lib/plat/unix/unix-sockets.c

@@ -28,7 +28,11 @@
 #include "private-lib-core.h"
 
 #include <sys/ioctl.h>
+
+#if !defined(LWS_DETECTED_PLAT_IOS)
 #include <net/route.h>
+#endif
+
 #include <net/if.h>
 
 #include <pwd.h>