user: implement mlibc as the libc, finally.

It's finally done..

Signed-off-by: kaguya <vpshinomiya@protonmail.com>

user/include/mlibc/options/posix/generic/utime.cpp

@@ -0,0 +1,31 @@
+
+#include <utime.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <bits/ensure.h>
+#include <mlibc/posix-sysdeps.hpp>
+
+int utime(const char *filename, const struct utimbuf *times) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_utimensat, -1);
+	struct timespec time[2];
+	if(times) {
+		time[0].tv_sec = times->actime;
+		time[0].tv_nsec = 0;
+		time[1].tv_sec = times->modtime;
+		time[1].tv_nsec = 0;
+	} else {
+		time[0].tv_sec = UTIME_NOW;
+		time[0].tv_nsec = UTIME_NOW;
+		time[1].tv_sec = UTIME_NOW;
+		time[1].tv_nsec = UTIME_NOW;
+	}
+
+	if (int e = mlibc::sys_utimensat(AT_FDCWD, filename, time, 0); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+