fix: build on Windows

tests/fmemopen.c

@@ -0,0 +1,41 @@
+#ifdef _WIN32
+#include <windows.h>
+#include "fmemopen.h"
+#include <share.h>
+#include <io.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+/* https://github.com/Arryboom/fmemopen_windows  */
+
+FILE *fmemopen(void *buf, size_t len, __attribute__((unused)) const char *type)
+{
+	int fd;
+	FILE *fp;
+	char tp[MAX_PATH - 13];
+	char fn[MAX_PATH + 1];
+	int * pfd = &fd;
+	int retner = -1;
+	char tfname[] = "MemTF_";
+	if (!GetTempPathA(sizeof(tp), tp))
+		return NULL;
+	if (!GetTempFileNameA(tp, tfname, 0, fn))
+		return NULL;
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wimplicit-function-declaration" //msys not happy
+	retner = _sopen_s(pfd, fn, _O_CREAT | _O_SHORT_LIVED | _O_TEMPORARY | _O_RDWR | _O_BINARY | _O_NOINHERIT, _SH_DENYRW, _S_IREAD | _S_IWRITE);
+#pragma GCC diagnostic pop
+	if (retner != 0)
+		return NULL;
+	if (fd == -1)
+		return NULL;
+	fp = _fdopen(fd, "wb+");
+	if (!fp) {
+		_close(fd);
+		return NULL;
+	}
+	/*File descriptors passed into _fdopen are owned by the returned FILE * stream.If _fdopen is successful, do not call _close on the file descriptor.Calling fclose on the returned FILE * also closes the file descriptor.*/
+	fwrite(buf, len, 1, fp);
+	rewind(fp);
+	return fp;
+}
+#endif