[Partial] Build wasi-libc for Windows (#2338)

Build wasi-libc library on Windows since libuv may be not supported. This PR is a first step
to make it working, but there's still a number of changes to get it fully working.

core/shared/platform/windows/platform_internal.h

@@ -57,6 +57,11 @@ typedef void *korp_tid;
 typedef void *korp_mutex;
 typedef void *korp_sem;
 
+typedef struct {
+    SRWLOCK lock;
+    bool exclusive;
+} korp_rwlock;
+
 /**
  * Create the mutex when os_mutex_lock is called, and no need to
  * CloseHandle() for the static lock's lifetime, since

core/shared/platform/windows/win_socket.c

@@ -206,6 +206,14 @@ os_socket_inet_network(bool is_ipv4, const char *cp, bh_ip_addr_buffer_t *out)
     return BHT_OK;
 }
 
+int
+os_socket_connect(bh_socket_t socket, const char *addr, int port)
+{
+    errno = ENOSYS;
+
+    return BHT_ERROR;
+}
+
 int
 os_socket_addr_resolve(const char *host, const char *service,
                        uint8_t *hint_is_tcp, uint8_t *hint_is_ipv4,

core/shared/platform/windows/win_thread.c

@@ -541,6 +541,62 @@ os_mutex_unlock(korp_mutex *mutex)
     return ReleaseMutex(*mutex) ? BHT_OK : BHT_ERROR;
 }
 
+int
+os_rwlock_init(korp_rwlock *lock)
+{
+    bh_assert(lock);
+
+    InitializeSRWLock(&(lock->lock));
+    lock->exclusive = false;
+
+    return BHT_OK;
+}
+
+int
+os_rwlock_rdlock(korp_rwlock *lock)
+{
+    bh_assert(lock);
+
+    AcquireSRWLockShared(&(lock->lock));
+
+    return BHT_OK;
+}
+
+int
+os_rwlock_wrlock(korp_rwlock *lock)
+{
+    bh_assert(lock);
+
+    AcquireSRWLockExclusive(&(lock->lock));
+    lock->exclusive = true;
+
+    return BHT_OK;
+}
+
+int
+os_rwlock_unlock(korp_rwlock *lock)
+{
+    bh_assert(lock);
+
+    if (lock->exclusive) {
+        lock->exclusive = false;
+        ReleaseSRWLockExclusive(&(lock->lock));
+    }
+    else {
+        ReleaseSRWLockShared(&(lock->lock));
+    }
+
+    return BHT_OK;
+}
+
+int
+os_rwlock_destroy(korp_rwlock *lock)
+{
+    (void)lock;
+
+    return BHT_OK;
+}
+
 int
 os_cond_init(korp_cond *cond)
 {