hyperlight-libc 0.16.0

This crate provides picolibc for Hyperlight guests. It builds the picolibc library and generates bindings to the libc types and functions.
Documentation
/*-
 * Copyright (c) 1988 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that: (1) source distributions retain this entire copyright
 * notice and comment, and (2) distributions including binaries display
 * the following acknowledgement:  ``This product includes software
 * developed by the University of California, Berkeley and its contributors''
 * in the documentation or other materials provided with the distribution.
 * Neither the name of the University nor the names of its
 * contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#define _DEFAULT_SOURCE
#include <stdlib.h>
#include <string.h>

int
putenv(char *str)
{
    register char *p, *equal;
    int            rval;

    p = strdup(str);

    if (!p)
        return 1;

    if (!(equal = strchr(p, '='))) {
        (void)free(p);
        return 1;
    }

    *equal = '\0';
    rval = setenv(p, equal + 1, 1);
    (void)free(p);

    return rval;
}