user: implement mlibc as the libc, finally.

It's finally done..

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

user/include/mlibc/options/ansi/musl-generic-math/__fpclassifyf.c

@@ -0,0 +1,11 @@
+#include <math.h>
+#include <stdint.h>
+
+int __fpclassifyf(float x)
+{
+	union {float f; uint32_t i;} u = {x};
+	int e = u.i>>23 & 0xff;
+	if (!e) return u.i<<1 ? FP_SUBNORMAL : FP_ZERO;
+	if (e==0xff) return u.i<<9 ? FP_NAN : FP_INFINITE;
+	return FP_NORMAL;
+}