rem: ucontext_t* uc = extra;
add: struct kernel_ucontext* uc = extra;
context: static void blomcall_resume_handler(int x, siginfo_t* si, void* extra) {  ucontext_t* uc = extra;  assert (blomcall_ctx != NULL);  // fpregs is a pointer in Linux!  struct _libc_fpstate* fpp = uc->uc_mcontext.fpregs;  *uc = blomcall_ctx->uc;  *fpp = blomcall_ctx->fp;  uc->uc_mcontext.fpregs = fpp;/*   printf("restoring state from context %p at %p, stack %p\n", *//* 	 blomcall_ctx, uc->uc_mcontext.gregs[REG_EIP], uc->uc_mcontext.gregs[REG_ESP]); */}