Add platform files for porting to MSVC

Add msvc.c and msvc.h to build git under MSVC.

Signed-off-by: Frank Li <lznuaa@gmail.com>
Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com>
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

compat/msvc.c

@@ -0,0 +1,35 @@
+#include "../git-compat-util.h"
+#include "win32.h"
+#include <conio.h>
+#include "../strbuf.h"
+
+DIR *opendir(const char *name)
+{
+	int len;
+	DIR *p;
+	p = (DIR*)malloc(sizeof(DIR));
+	memset(p, 0, sizeof(DIR));
+	strncpy(p->dd_name, name, PATH_MAX);
+	len = strlen(p->dd_name);
+	p->dd_name[len] = '/';
+	p->dd_name[len+1] = '*';
+
+	if (p == NULL)
+		return NULL;
+
+	p->dd_handle = _findfirst(p->dd_name, &p->dd_dta);
+
+	if (p->dd_handle == -1) {
+		free(p);
+		return NULL;
+	}
+	return p;
+}
+int closedir(DIR *dir)
+{
+	_findclose(dir->dd_handle);
+	free(dir);
+	return 0;
+}
+
+#include "mingw.c"