Use posix_win.c functions on WIN32

- read() returns bytes count as 1 for crlf unless binary mode isn't
  specified with open(). Reported by @ulfworsoe in libressl-portable#542
- err could be WSANOTINITIALISED when WSAStartup() is not called

patches/keypairtest.c.patch

@@ -1,13 +0,0 @@
---- tests/keypairtest.c.orig	Sun Mar 18 00:31:20 2018
-+++ tests/keypairtest.c	Sun Mar 18 00:31:33 2018
-@@ -15,6 +15,10 @@
-  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-  */
- 
-+#ifdef _MSC_VER
-+#define NO_REDEF_POSIX_FUNCTIONS
-+#endif
-+
- #include <sys/stat.h>
- 
- #include <err.h>

patches/tls_config.c.patch

@@ -1,25 +0,0 @@
---- tls/tls_config.c.orig	Fri Jul 26 22:16:53 2019
-+++ tls/tls_config.c	Fri Jul 26 22:21:25 2019
-@@ -15,6 +15,10 @@
-  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-  */
- 
-+#ifdef _MSC_VER
-+#define NO_REDEF_POSIX_FUNCTIONS
-+#endif
-+
- #include <sys/stat.h>
- 
- #include <ctype.h>
-@@ -48,7 +52,11 @@ tls_config_load_file(struct tls_error *error, const ch
- 	*buf = NULL;
- 	*len = 0;
- 
-+#ifndef _WIN32
- 	if ((fd = open(filename, O_RDONLY)) == -1) {
-+#else
-+	if ((fd = open(filename, O_RDONLY | O_BINARY)) == -1) {
-+#endif
- 		tls_error_set(error, "failed to open %s file '%s'",
- 		    filetype, filename);
- 		goto err;

patches/tls_util.c.patch

@@ -1,25 +0,0 @@
---- tls/tls_util.c.orig	Fri Jul 26 22:17:04 2019
-+++ tls/tls_util.c	Fri Jul 26 22:21:22 2019
-@@ -17,6 +17,10 @@
-  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-  */
- 
-+#ifdef _MSC_VER
-+#define NO_REDEF_POSIX_FUNCTIONS
-+#endif
-+
- #include <sys/stat.h>
- 
- #include <stdlib.h>
-@@ -161,7 +165,11 @@ tls_load_file(const char *name, size_t *len, char *pas
- 
- 	*len = 0;
- 
-+#ifndef _WIN32
- 	if ((fd = open(name, O_RDONLY)) == -1)
-+#else
-+	if ((fd = open(name, O_RDONLY | O_BINARY)) == -1)
-+#endif
- 		return (NULL);
- 
- 	/* Just load the file into memory without decryption */