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

fusl/src/misc/getrlimit.c

+#include <sys/resource.h>
+#include <errno.h>
+#include "syscall.h"
+#include "libc.h"
+
+#define FIX(x) do{ if ((x)>=SYSCALL_RLIM_INFINITY) (x)=RLIM_INFINITY; }while(0)
+
+int getrlimit(int resource, struct rlimit *rlim)
+{
+        unsigned long k_rlim[2];
+        int ret = syscall(SYS_prlimit64, 0, resource, 0, rlim);
+        if (!ret) {
+                FIX(rlim->rlim_cur);
+                FIX(rlim->rlim_max);
+        }
+        if (!ret || errno != ENOSYS)
+                return ret;
+        if (syscall(SYS_getrlimit, resource, k_rlim) < 0)
+                return -1;
+        rlim->rlim_cur = k_rlim[0] == -1UL ? RLIM_INFINITY : k_rlim[0];
+        rlim->rlim_max = k_rlim[1] == -1UL ? RLIM_INFINITY : k_rlim[1];
+        FIX(rlim->rlim_cur);
+        FIX(rlim->rlim_max);
+        return 0;
+}
+
+LFS64(getrlimit);