user: implement mlibc as the libc, finally.

It's finally done..

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

user/include/mlibc/options/bsd/generic/bsd_stdlib.cpp

@@ -0,0 +1,27 @@
+
+#include <errno.h>
+#include <bits/ensure.h>
+
+#include <stdlib.h>
+
+#include <mlibc/bsd-sysdeps.hpp>
+
+int getloadavg(double *samples, int nsample) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getloadavg, -1);
+	if (nsample < 0) {
+		errno = EINVAL;
+		return -1;
+	}
+	if (nsample > 3) {
+		nsample = 3;
+	}
+	double s[3];
+	if (int e = sysdep(s); e) {
+		errno = e;
+		return -1;
+	}
+	for (int i = 0; i < nsample; i++) {
+		samples[i] = s[i];
+	}
+	return nsample;
+}