Add a "fork" of musl as //fusl.

fusl/src/linux/prlimit.c

+#define _GNU_SOURCE
+#include <sys/resource.h>
+#include "syscall.h"
+#include "libc.h"
+
+#define FIX(x) do{ if ((x)>=SYSCALL_RLIM_INFINITY) (x)=RLIM_INFINITY; }while(0)
+
+int prlimit(pid_t pid, int resource, const struct rlimit *new_limit, struct rlimit *old_limit)
+{
+        struct rlimit tmp;
+        int r;
+        if (new_limit && SYSCALL_RLIM_INFINITY != RLIM_INFINITY) {
+                tmp = *new_limit;
+                FIX(tmp.rlim_cur);
+                FIX(tmp.rlim_max);
+                new_limit = &tmp;
+        }
+        r = syscall(SYS_prlimit64, pid, resource, new_limit, old_limit);
+        if (!r && old_limit && SYSCALL_RLIM_INFINITY != RLIM_INFINITY) {
+                FIX(old_limit->rlim_cur);
+                FIX(old_limit->rlim_max);
+        }
+        return r;
+}
+
+#undef prlimit64
+LFS64(prlimit);