Extend os_mmap to support map file from fd (#2763)

Add an extra argument `os_file_handle file` for `os_mmap` to support
mapping file from a file fd, and remove `os_get_invalid_handle` from
`posix_file.c` and `win_file.c`, instead, add it in the `platform_internal.h`
files to remove the dependency on libc-wasi.

Signed-off-by: Huang Qi <huangqi3@xiaomi.com>

core/shared/platform/rt-thread/platform_internal.h

@@ -49,4 +49,10 @@ typedef int os_file_handle;
 typedef DIR *os_dir_stream;
 typedef int os_raw_file_handle;
 
+static inline os_file_handle
+os_get_invalid_handle()
+{
+    return -1;
+}
+
 #endif /* RTTHREAD_PLATFORM_INTERNAL_H */

core/shared/platform/rt-thread/rtt_platform.c

@@ -191,7 +191,7 @@ os_cond_wait(korp_cond *cond, korp_mutex *mutex)
 }
 
 void *
-os_mmap(void *hint, size_t size, int prot, int flags)
+os_mmap(void *hint, size_t size, int prot, int flags, os_file_handle file)
 {
     return rt_malloc(size);
 }