Add RTX-RTOS support

mongoose.h

@@ -35,6 +35,7 @@ extern "C" {
 #define MG_ARCH_FREERTOS_TCP 5
 #define MG_ARCH_FREERTOS_LWIP 6
 #define MG_ARCH_AZURERTOS 7
+#define MG_ARCH_RTX_LWIP 8
 
 #if !defined(MG_ARCH)
 #if defined(__unix__) || defined(__APPLE__)
@@ -287,6 +288,46 @@ struct timeval {
 #endif  // MG_ARCH == MG_ARCH_FREERTOS_TCP
 
 
+#if MG_ARCH == MG_ARCH_RTX_LWIP
+
+#include <ctype.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+#if defined(__GNUC__)
+#include <sys/stat.h>
+#include <sys/time.h>
+#else
+struct timeval {
+  time_t tv_sec;
+  long tv_usec;
+};
+#endif
+
+#include <lwip/sockets.h>
+
+#if LWIP_SOCKET != 1
+// Sockets support disabled in LWIP by default
+#error Set LWIP_SOCKET variable to 1 (in lwipopts.h)
+#endif
+
+#define mkdir(a, b) (-1)
+
+#ifndef MG_IO_SIZE
+#define MG_IO_SIZE 512
+#endif
+
+#ifndef MG_PATH_MAX
+#define MG_PATH_MAX 128
+#endif
+
+
+#endif
+
+
 #if MG_ARCH == MG_ARCH_UNIX
 
 #define _DARWIN_UNLIMITED_SELECT 1  // No limit on file descriptors