Snippets for pth 2.0.7 from Nix aarch64-linux

Sourced from https://hydra.nixos.org/log/p7sjjlpmpjkc4iixjjhs2jj603sl5rfd-pth-2.0.7.drv.

• pth_debug.c:75:16: warning: ignoring return value of 'write' declared with attribute 'warn_unused_result' [-Wunused-result]
     75 |         pth_sc(write)(STDERR_FILENO, str, n);
        |                ^
  

• pth_sched.c:851:12: warning: ignoring return value of 'write' declared with attribute 'warn_unused_result' [-Wunused-result]
    851 |     pth_sc(write)(pth_sigpipe[1], &c, sizeof(char));
        |            ^
  

• test_uctx.c:45:22: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
     45 |     volatile int n = (int)ctx;
        |                      ^
  

• test_uctx.c:71:61: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
     71 |         pth_uctx_make(uctx[i], NULL, 32*1024, NULL, worker, (void *)i, uctx[0]);
        |                                                             ^