user: implement mlibc as the libc, finally.

It's finally done..

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

user/include/mlibc/sysdeps/linux/generic/entry.cpp

@@ -0,0 +1,18 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <bits/ensure.h>
+#include <mlibc/elf/startup.h>
+#include <sys/auxv.h>
+
+extern "C" void __dlapi_enter(uintptr_t *);
+
+extern char **environ;
+
+size_t __hwcap;
+
+extern "C" void __mlibc_entry(uintptr_t *entry_stack, int (*main_fn)(int argc, char *argv[], char *env[])) {
+	__dlapi_enter(entry_stack);
+	__hwcap = getauxval(AT_HWCAP);
+	auto result = main_fn(mlibc::entry_stack.argc, mlibc::entry_stack.argv, environ);
+	exit(result);
+}