SIG_IGN does not compile

[Thierry Delisle]

This code fails to compile:

#include <signal.h>

int main() {
	SIG_IGN;
}

It tries to cast 1 to a function pointer and cforall refuses:

test.c:4:1 error: Invalid application of existing declaration(s) in expression Explicit Cast of:
  Constant Expression (1: one_t)
  ... with resolved type:
    one_t
... to:
  pointer to function
  ... with parameters
    signed int
  ... returning nothing

... with resolved type:
  pointer to function
  ... with parameters
    signed int
  ... returning nothing

This is a backwards compatibility problem.