doesn't compile on Windows 10

[AntonOks]

Hi.

• go version go1.14.2 windows/amd64
• Windows 10, 1909

C:\Users\me\go\src\github.com\s3git\s3git>go install
# github.com/bmatsuo/lmdb-go/lmdb
mdb.c: In function 'mdb_env_setup_locks':
mdb.c:4853:17: warning: implicit declaration of function 'pthread_mutexattr_setrobust'; did you mean 'pthread_mutexattr_settype'? [-Wimplicit-function-declaration]
   if (!rc) rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST);
                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~
                 pthread_mutexattr_settype
mdb.c:4853:53: error: 'PTHREAD_MUTEX_ROBUST' undeclared (first use in this function); did you mean 'PTHREAD_MUTEX_DEFAULT'?
   if (!rc) rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST);
                                                     ^~~~~~~~~~~~~~~~~~~~
                                                     PTHREAD_MUTEX_DEFAULT
mdb.c:4853:53: note: each undeclared identifier is reported only once for each function it appears in
mdb.c: In function 'mdb_mutex_failed':
mdb.c:362:37: warning: implicit declaration of function 'pthread_mutex_consistent'; did you mean 'pthread_mutex_init'? [-Wimplicit-function-declaration]
 #define mdb_mutex_consistent(mutex) pthread_mutex_consistent(mutex)
                                     ^
mdb.c:10193:10: note: in expansion of macro 'mdb_mutex_consistent'
    rc2 = mdb_mutex_consistent(mutex);
          ^~~~~~~~~~~~~~~~~~~~
mdb.c: In function 'mdb_cursor_put':
mdb.c:6725:9: warning: this statement may fall through [-Wimplicit-fallthrough=]
      if (SIZELEFT(fp) < offset) {
         ^
mdb.c:6730:5: note: here
     case MDB_CURRENT:
     ^~~~
go: failed to remove work dir: GetFileInformationByHandle C:\Users\me\AppData\Local\Temp\go-build863785342\NUL: Incorrect function.